Binaries generated for Cortex-M33 targets (e.g. Musca S1/B1) using
the Arm toolchain + CMake is unable to run, unless we instruct the
linker to not use floating points.
Note: This is a temporary workaround, because
* Ideally, the Arm linker should be able to auto detect the
architecture support from the input object files, but it's not
always the case. We already have a similar workaround for Cortex-M4.
* The full option to use should be `--cpu=Cortex-M33.no_dsp.no_fp`
but `no_dsp` currently conflicts with CMake's compilation tests
(no option to disable DSP in the test objects before linking).
The GCC flag to specify the floating-point hardware (`mfpu`) does not accept
the value `none`. The default value is `auto` which causes the compiler to
select the floating-point and Advanced SIMD instructions based on the
settings of -mcpu and -march. The extension option `+nofp` has been added
to disable floating point instructions.
Move the fpu settings across all cores so they are aligned.
Some cores did not have fpu set for ARMClang. I matched here both toolchains to set up
the fpu the same (Only exception is soft vs hard - that is separate issue I would not like to touch
in this series).
Set DOMAIN_NS=1 only for _NS cores. We had it otherway around.
I verified one non NS target that was failing to build, plus also checked the old tools
that had this definitions:
```
91: "Cortex-M23-NS": ["__CORTEX_M23", "ARM_MATH_ARMV8MBL", "DOMAIN_NS=1",
92 "__CMSIS_RTOS", "__MBED_CMSIS_RTOS_CM"],
93 "Cortex-M23": ["__CORTEX_M23", "ARM_MATH_ARMV8MBL", "__CMSIS_RTOS",
94 "__MBED_CMSIS_RTOS_CM"],
```
The new function (mbed_set_cpu_core_definitions()) should always be
called as it has defintions needed by Mbed OS to work with that
particular MCU core.
mbed_set_cpu_core_options() should only be called if a third-party
toolchain file has not been used as it has compile options that can
cause conflicts.
Lingkai Dong
Hugues Kamba
Martin Kojtal
Jamie Smith
Rajkumar Kanagaraj