STM32: solve GCC Unspecified RTOS error

[jeromecoutant]

Summary of changes

While testing latest mbed-os-6.0.0-alpha-3, I could see several crash with GCC:

[1585061544.23][CONN][RXD] ++ MbedOS Error Info ++
[1585061544.23][CONN][RXD] Error Status: 0x80010131 Code: 305 Module: 1
[1585061544.23][CONN][RXD] Error Message: Kernel Error: 0xFFFFFFFF, Unspecified RTOS error
[1585061544.23][CONN][RXD] Location: 0x8003E2F
[1585061544.23][CONN][RXD] Error Value: 0xFFFFFFFF
[1585061544.23][CONN][RXD] Current Thread: <unnamed> Id: 0x0 Entry: 0x80040C9 StackSize: 0x0 StackMem: 0x8007CD5 SP: 0x2002FF4C
[1585061544.23][CONN][RXD] For more info, visit: https://mbed.com/s/error?error=0x80010131&tgt=NUCLEO_WB55RG
[1585061544.23][CONN][RXD] -- MbedOS Error Info --

Impact of changes

Impacted targets are the latest one integrated in mbed-os...

Migration actions required

Documentation

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Pull request type

[x] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results

[] No Tests required for this change (E.g docs only update)
[x] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

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Reviewers

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[ciarmcom]

@jeromecoutant, thank you for your changes.
@ARMmbed/mbed-os-maintainers please review.

[0xc0170]

I do not understand alignment removal - how does it fix and what error is it?

[jeromecoutant]

I do not understand alignment removal - how does it fix and what error is it?

I don't know, I checked the difference between before and now..
And it works...

[0xc0170]

I still would like to find out why was that comment there (curiosity , as I do not fully understand the fix it was applied there).

[0xc0170]

CI started

[mbed-ci]

Test run: FAILED

Summary: 1 of 6 test jobs failed
Build number : 2
Build artifacts

Failed test jobs:

• jenkins-ci/mbed-os-ci_greentea-test