MSan's `timer_create()` interceptor uses incorrect type for `tv_nsec` member

[chrisburel]

In this code:

llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.h

Lines 400 to 403 in 5f38548

	struct __sanitizer_timespec {
	__sanitizer_time_t tv_sec; /* seconds */
	u64 tv_nsec; /* nanoseconds */
	};

__sanitizer_timespec.tv_nsec is declared to be the fixed-size type u64. This does not match the standard, which specifies that the type be:

• long for <C23
• some implementation-defined signed integer type that can represent integers in [​0​, 999999999], for >=C23

This causes false positives when mixing libraries that are instrumented with libraries that are not, on 32-bit platforms. Calling timer_create() -> timer_settime() -> timer_gettime() will cause an incorrect report of a stack-buffer-overflow with WRITE of size 32.