[compiler-rt] Use .globl for FreeBSD/NetBSD interceptor wrappers

[jrtc27]

Summary

On FreeBSD and NetBSD we don't use .weak due to differing semantics.
Currently we end up using no directive, which gives a local symbol,
whereas the closer thing to a weak symbol would be a global one. In
particular, both GNU and LLVM toolchains cannot handle a GOT-indirect
reference to a local symbol at a non-zero offset within a section on
AArch64 (see https://github.com/ARM-software/abi-aa/issues/217), and so
interceptors do not work on FreeBSD/arm64, failing to link with LLD.
Switching to .globl both works around this bug and more closely aligns
such non-weak platforms with weak ones.

Fixes https://github.com/llvm/llvm-project/issues/63418

compiler-rt/lib/interception/interception.h

 // We use inline assembly to define most of this, because not all compilers
 // support functions with the "naked" attribute with every architecture.
 #  define WRAP(x) ___interceptor_ ## x
 #  define TRAMPOLINE(x) __interceptor_trampoline_ ## x
 #  if SANITIZER_FREEBSD || SANITIZER_NETBSD
 // FreeBSD's dynamic linker (incompliantly) gives non-weak symbols higher
 // priority than weak ones so weak aliases won't work for indirect calls
 // in position-independent (-fPIC / -fPIE) mode.
-#   define __ASM_WEAK_WRAPPER(func)
+#   define __ASM_WEAK_WRAPPER(func) ".globl " #func "\n"
 #  else
 #   define __ASM_WEAK_WRAPPER(func) ".weak " #func "\n"
 #  endif  // SANITIZER_FREEBSD || SANITIZER_NETBSD
 // Keep trampoline implementation in sync with sanitizer_common/sanitizer_asm.h
 #  define DECLARE_WRAPPER(ret_type, func, ...)                                 \
      extern "C" ret_type func(__VA_ARGS__);                                    \
      extern "C" ret_type TRAMPOLINE(func)(__VA_ARGS__);                        \
      extern "C" ret_type __interceptor_##func(__VA_ARGS__)                     \