Fix __PROGRAM_START definition for TI Arm Clang (tiarmclang)

[Copilot]

CMSIS_6 routes tiarmclang through cmsis_clang.h/cmsis_clang_m.h, which unconditionally defines __PROGRAM_START as _start. TI Arm Clang's actual C runtime entry point is _c_int00, so this causes link failures that didn't occur with CMSIS_5 (which special-cased tiarmclang correctly).

Changes

• In CMSIS/Core/Include/m-profile/cmsis_clang_m.h, define __PROGRAM_START as _c_int00 when __ti__ is defined (TI Arm Clang), falling back to _start for all other Clang-based compilers.

#ifndef __PROGRAM_START
#if defined (__ti__)
#define __PROGRAM_START           _c_int00
#else
#define __PROGRAM_START           _start
#endif
#endif

__ti__ is the identifier tiarmclang already defines and is used consistently elsewhere in the codebase (cmsis_compiler.h, various core_*.h files) to distinguish TI Arm Clang from other Clang-based toolchains.

• Fixes compile failed when use tiarmclang 5.1.1 #312

[github-actions]

Test Results

   644 files  ±0     644 suites  ±0   15m 4s ⏱️ + 3m 53s
    49 tests ±0      44 ✅ ±0       5 💤 ±0  0 ❌ ±0 
31 556 runs  ±0  20 156 ✅ ±0  11 400 💤 ±0  0 ❌ ±0 

Results for commit 1df8fc7. ± Comparison against base commit 8827df2.

♻️ This comment has been updated with latest results.