tsan: fix GCC warnings

[marxin]

Summary

Fixes:

tsan/tsan_shadow.h:93:32: warning: enumerated and non-enumerated type in conditional expression [-Wextra]
tsan/tsan_shadow.h:94:44: warning: enumerated and non-enumerated type in conditional expression [-Wextra]

[dvyukov]

compiler-rt/lib/tsan/rtl/tsan_shadow.h

91–97

This implicitly hardcodes that kAccessWrite==0. While it's unlikely to change, it's possible.
I think it will be cleaner with:

if (part_.is_atomic_)
  *typ |= kAccessAtomic;

[marxin]

V2 of the patch.

compiler-rt/lib/tsan/rtl/tsan_shadow.h

public:
 
   void GetAccess(uptr *addr, uptr *size, AccessType *typ) const {
     DCHECK(part_.access_ != 0 || raw_ == static_cast<u32>(Shadow::kRodata));
     if (addr)
       *addr = part_.access_ ? __builtin_ffs(part_.access_) - 1 : 0;
     if (size)
       *size = part_.access_ == kFreeAccess ? kShadowCell
                                            : __builtin_popcount(part_.access_);
-    if (typ)
-      *typ = (part_.is_read_ ? kAccessRead : kAccessWrite) |
-             (part_.is_atomic_ ? kAccessAtomic : 0) |
-             (part_.access_ == kFreeAccess ? kAccessFree : 0);
+    if (typ) {
+      *typ = part_.is_read_ ? kAccessRead : kAccessWrite;
+      if (part_.is_atomic_)
+        *typ |= kAccessAtomic;
+      if (part_.access_ == kFreeAccess)
+        *typ |= kAccessFree;
+    }
   }
 
   ALWAYS_INLINE
   bool IsBothReadsOrAtomic(AccessType typ) const {
     u32 is_read = !!(typ & kAccessRead);
     u32 is_atomic = !!(typ & kAccessAtomic);
     bool res =
         raw_ & ((is_atomic << kIsAtomicShift) | (is_read << kIsReadShift));