[clang] Fix remove{CVR|Fast}Qualifiers with 64-bit Qualifiers::Mask

After llvm#84384, `Qualifiers::Mask` becomes 64-bit. So, operations like
`Mask &= ~U32` where `U32` is `unsigned` produce undesirable results
since higher 32 bits of `Mask` become zeroed while they should be
preserved. Fix that by explicitly casting `unsigned` values to `uint64_t`
in such operations. Signatures of fixed functions are intentionally left
intact instead of changing the argument itself to `uint64_t` to keep things
consistent with other functions working with the same qualifiers and to
emphasize that 64-bit masks should not be used for these types of
qualifiers.

Author: kovdan01

clang/include/clang/AST/Type.h

@@ -480,7 +480,7 @@ class Qualifiers {
   }
   void removeCVRQualifiers(unsigned mask) {
     assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
-    Mask &= ~mask;
+    Mask &= ~static_cast<uint64_t>(mask);
   }
   void removeCVRQualifiers() {
     removeCVRQualifiers(CVRMask);
@@ -609,7 +609,7 @@ class Qualifiers {
   }
   void removeFastQualifiers(unsigned mask) {
     assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
-    Mask &= ~mask;
+    Mask &= ~static_cast<uint64_t>(mask);
   }
   void removeFastQualifiers() {
     removeFastQualifiers(FastMask);