[hwasan] Fix -Wunneeded-internal-declaration by declaring static inline

[thurston]

Summary

https://reviews.llvm.org/D149386 caused a buildbot error (https://lab.llvm.org/buildbot#builders/37/builds/21766):

'In file included from /b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/hwasan/hwasan_interceptors.cpp:18:
/b/sanitizer-x86_64-linux/build/llvm-project/compiler-rt/lib/hwasan/hwasan_checks.h:128:53: error: 'static' function 'PossiblyShortTagMatches' declared in header file should be declared 'static inline' [-Werror,-Wunneeded-internal-declaration]
attribute((always_inline, nodebug)) static bool PossiblyShortTagMatches('

This patch simply adds the inline annotation.

[thurston]

I submitted this to unbreak the build. Please post-commit audit instead: https://reviews.llvm.org/rG81d06268f47f089335076eb608c880fc0e60a677

compiler-rt/lib/hwasan/hwasan_checks.h

asm volatile(
       "addiw x0, x0, %2\n" ::"r"(x10),
       "r"(x11), "I"(0x40 + SigTrapEncoding(EA, AT)));
 #else
   __builtin_trap();
 #endif
   // __builtin_unreachable();
 }
 
-__attribute__((always_inline, nodebug)) static bool PossiblyShortTagMatches(
-    tag_t mem_tag, uptr ptr, uptr sz) {
+__attribute__((always_inline, nodebug)) static inline bool
+PossiblyShortTagMatches(tag_t mem_tag, uptr ptr, uptr sz) {
   tag_t ptr_tag = GetTagFromPointer(ptr);
   if (ptr_tag == mem_tag)
     return true;
   if (mem_tag >= kShadowAlignment)
     return false;
   if ((ptr & (kShadowAlignment - 1)) + sz > mem_tag)
     return false;
 #if !defined(__aarch64__) && !(SANITIZER_RISCV64)