Merge pull request #13276 from davezarzycki/nfc_fix_warning

Author: swift-ci

include/swift/AST/Types.h

@@ -309,7 +309,7 @@ class alignas(1 << TypeAlignInBits) TypeBase {
     unsigned : NumTypeBaseBits;
 
     /// \brief The unique number assigned to this type variable.
-    unsigned ID : 64 - NumTypeBaseBits;
+    uint64_t ID : 64 - NumTypeBaseBits;
   };
   NUMBITS(TypeVariableType, 64);