FATFileSystem::stat() enabled for all compilers

[michalpasztamobica]

Description

Fixes #10198
Macro which restricted compilation to GCC_ARM is removed.
Existing read_write() test is amended to call stat() and check that correct size is returned.

Pull request type

[x] Fix
[ ] Refactor
[ ] Target update
[ ] Functionality change
[ ] Docs update
[ ] Test update
[ ] Breaking change

Reviewers

@SeppoTakalo
@geky
@kjbracey-arm

[ciarmcom]

@michalpasztamobica, thank you for your changes.
@kjbracey-arm @SeppoTakalo @geky @ARMmbed/mbed-os-storage @ARMmbed/mbed-os-maintainers please review.

[kjbracey]

Can you check if this breaks ARMC5? You might want to have a #ifndef __CC_ARM there for that.

Despite lack of official support or testing, if it's easy to avoid breakage, we should.

[michalpasztamobica]

@kjbracey-arm , I checked that the proposed changes compile fine with:

Product: DS-5 Ultimate Edition 5.29.2
Component: ARM Compiler 5.06 update 3 (build 300)

and the test (as modified in this review) passed.

[kjbracey]

Cool. I wonder why it was originally thought not to work on ARMCC then?

[michalpasztamobica]

To my understanding the reasons were twofold: 1) not enough testing to be sure that this worked 2) even if the testing was there and indicated an issue a couple of years ago, then both IAR and ARM compiler improved since then - the #ifdef is 3 years old and might have been copied from an even older location, unchanged.

[0xc0170]

CI restarted

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 1
Build artifacts