semihosting: add compat header where is required ...

ARMCC provides __semihost via compat header. As CMSIS 5.8.0 removed this compat header,
we need to explicitly include it to fix definition missing error.

retarget: move compat header for ARMClang prior any cmsis headers ...

Reference: CMSIS 5.8.0 known issues and https://github.com/ARM-software/CMSIS_5/issues/1211

This fixes the error about redefinition of enable/disable irq. we need compat header because of
semihosting (not yet provided in CMSIS).

CMake: unittests: Show all tests in CTest report ...

Previously a test executable was recognised as a single test by CTest.
However, test executables usually contain multiple test cases, the
results of the test cases should be individually reported. With our
previous setup we could miss test case failures that didn't cause the
executable to return an error code.

This commit uses gtest_discover_test to discover all test cases in a
test executable. This enables CTest to match test passes and failures
from the googletest binary output.

Merge pull request #14948 from Patater/lorawan-timer-unittest-fake-fix ...

Fix lorawantimer unit test

test: Make MBED_ASSERT failures fail ...

Make MBED_ASSERT failures fail the unit test case. Without this, we
might not notice the assertion failure as it wouldn't be bubbled up to
googletest.

test: CircularBuffer: Don't push zero elements ...

The CircularBuffer doesn't allow pushing zero elements; you must push at
least one. Update the CircularBuffer unit test to avoid invalid use of
the CircularBuffer.

Merge pull request #14945 from OpenNuvoton/nuvoton_tfm_missing_update ...

TFM: Add missing IPC file for PSA Firmware Update

TFM: Add missing IPC file for PSA Firmware Update ...

On a target that doesn't support Firmware Update, compilation still works, and any attempt to call the Firmware Update API returns a runtime error which is good enough.

Rework post-build to support multiple executables ...

When building greentea tests, each test is an executable with its
own output binary path. This is also the case when a user project
produces multiple executables. But the current implementation of
post-build operations always assumes there's only one executable,
at the root of the build directory.

The post-build command depends on Mbed target, and it always takes
the the executable we build as an input file. To achieve this, we
let each Mbed target (that has a post-build command) define a function

    function(mbed_post_build_function target)

which takes a CMake executable target as an argument from which it can
get its binary path using generator expressions. It generates and adds
to the passed executable target a post-build custom command.

Notes:
* The function name needs to be exact, because CMake only supports
literal function calls - CMake can't dereference a function name from
a variable. To avoid multiple definitions of this function, each Mbed
target needs to guard it with a macro to check if the user is
building this Mbed target.
* `mbed_post_build_function()` is a function, but it is usually
defined by another macro rather than a parent function, because
nesting functions would make many variables inaccessible inside the
innermost `mbed_post_build_function()`.
* There's no more need to force regenerate images. Previously, post-
build commands were custom *targets* which always got to run, so we
force regenerated images on every build to avoid patching an image
that's already been patched once on previous build. Now post-build
commands are custom *commands* of the same executable target, and they
are only run if the executable target itself is rebuilt.

mbed_retarget: enable IAR build

Update Mbed version block

CMake: unit-tests: Remove --coverage option from mbed-stubs-platform ...

We set the --coverage flag globally in UNITTESTS/CMakeLists.txt. We
shouldn't need to also set it on mbed-stubs-platform, so remove it.

CMake: unit-tests: Split platform headers out of mbed-stubs-headers ...

We have a central collection of "stub headers", which makes reasoning
about dependencies rather difficult, as it forces every stub library to
depend on all available stub headers. The standard approach would be for
each stub library to expose its public headers, and its dependents to
explicitly specify a dependency on the stub library containing the
headers it needs. This is a more modular design than creating a
header-only monolith library. Move the platform stub headers from this
central library into the mbed-stubs-platform library to increase
modularity.

mbed-stubs-connectivity now depends on the mbed-stubs-platform because
it requires some headers which were moved to mbed-stubs-platform.

CMake: unit-tests: Make platform stub only depend on headers it uses ...

Previously the platform stub library depended on `mbed-headers`, which
is a collection of all available headers in mbed-os. To make it easier
to separate the library, only depend on the headers we're actually using.

CMake: unit-tests: Move mbed-headers-platform to platform directory ...

Move the header-only mbed-headers-platform library the unit test stubs
depend on into the platform component directory. This makes the platform
stubs more self contained and improves composition of the library.

CMake: Move platform stubs to the mbed-os/platform directory ...

Move the platform stub library into the platform component directory.
This change is so we can avoid duplicating the mbed-os source tree in a
central UNITTESTS folder.

CMake: unit-tests: CircularBuffer: Remove trailing whitespace

Merge pull request #14783 from rwalton-arm/dont_capture_stdout ...

tfm-post-build: Don't capture subprocess stdout

PSA: Fix compile error with NV seed ...

This compile error can reproduce when both PSA V7M and MBEDTLS_ENTROPY_NV_SEED are both enabled.

Merge pull request #14718 from Meano/develop ...

Feature: Make changes for Cortex-A5 support

Merge pull request #14816 from artokin/nanostack_release_14_0_0_master ...

Nanostack release v14.0.0

tfm-post-build: Don't capture subprocess stdout ...

subprocess.PIPE is used to enable the parent process to communicate with
the subprocess via pipes, which mean all stdout and stderr messages are
captured and returned as part of Popen.communicate's result tuple.

In our case, we want to display the error messages on the console, so we
don't need to capture the output from stdout.

Example of a typical error message before this change:
```
Traceback (most recent call last):
  File "platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/scripts/generate_mbed_image.py", line 197, in <module>
    sign_and_merge_tfm_bin(args.tfm_target, args.target_path, args.non_secure_bin, args.secure_bin)
  File "platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/scripts/generate_mbed_image.py", line 81, in sign_and_merge_tfm_bin
    " secure binary, Error code: " + str(retcode))
Exception: Unable to sign musca_b1 secure binary, Error code: 1
```

Example of the error message after this change:
```
Traceback (most recent call last):
  File "/mbed-os/tools/psa/tfm/bin_utils/wrapper.py", line 13, in <module>
    import click
ModuleNotFoundError: No module named 'click'
Traceback (most recent call last):
  File "platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/scripts/generate_mbed_image.py", line 194, in <module>
    sign_and_merge_tfm_bin(args.tfm_target, args.target_path, args.non_secure_bin, args.secure_bin)
  File "platform/FEATURE_EXPERIMENTAL_API/FEATURE_PSA/TARGET_TFM/TARGET_TFM_LATEST/scripts/generate_mbed_image.py", line 80, in sign_and_merge_tfm_bin
    raise Exception("Unable to sign " + target_name +
Exception: Unable to sign musca_b1 secure binary, Error code: 1
```

This is a significant improvement as now you can see what the reason for
the failure was.

Merge pull request #14828 from hazzlim/add-cmake-supports-psa-tests ...

CMake: Add CMake to mbed-psa greentea tests

CMake: Add support for PSA compliance_its tests ...

PSA compliance_its tests can now be built with CMake.

CMake: Add support for compliance_attestation test ...

Greentea test for PSA compliance_attestation can now build with CMake.

CMake: Add mbed-psa-tal (Test Abstraction Layers) ...

Move /val and /pal directories into /test_abstraction_layers directory
and combine into one CMake target, mbed-psa-tal. Moved into seperate
directory in order to have own CMakeLists.txt, rather than adding to
/TARGET_MBED_PSA_SRV CMake file.

CMake: Add support for PSA entropy_inject test ...

The greentea test for PSA entropy_inject can now be built with CMake.
Note: requires MBEDTLS_ENTROPY_NV_SEED enabled, so not tested on target.

CMake: Add support for PSA its_ps test ...

The greentea test for mbed-psa its_ps can now be built with CMake.

CMake: Add support for PSA crypto_init test ...

The greentea test for mbed-psa crypto_init can now be built with CMake.

CMake: Add support for PSA attestation test ...

The greentea test for mbed-psa attestation can now be built with CMake.