add preferred type annotations i inexplicably didn't add earlier and remove the MathExtras.h noise

Author: ojhunt

llvm/include/llvm/Demangle/ItaniumDemangle.h

@@ -2996,7 +2996,7 @@ template <typename Derived, typename Alloc> struct AbstractManglingParser {
     };
     char Enc[2];      // Encoding
     OIKind Kind;      // Kind of operator
-    bool Flag : 1;   // Entry-specific flag
+    bool Flag : 1;    // Entry-specific flag
     Node::Prec Prec : 7; // Precedence
     const char *Name; // Spelling
 

llvm/include/llvm/IR/User.h

@@ -79,7 +79,9 @@ class User : public Value {
   struct AllocInfo {
   public:
     const unsigned NumOps : NumUserOperandsBits;
+    LLVM_PREFERRED_TYPE(bool)
     const unsigned HasHungOffUses : 1;
+    LLVM_PREFERRED_TYPE(bool)
     const unsigned HasDescriptor : 1;
 
     AllocInfo() = delete;

llvm/include/llvm/Support/MathExtras.h

@@ -40,9 +40,6 @@ template <typename T, typename U, typename = enableif_int<T, U>>
 using common_sint =
     std::common_type_t<std::make_signed_t<T>, std::make_signed_t<U>>;
 
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wc++17-extensions"
-
 /// Mathematical constants.
 namespace numbers {
 // TODO: Track C++20 std::numbers.
@@ -80,8 +77,6 @@ constexpr float ef          = 0x1.5bf0a8P+1F, // (2.71828183) https://oeis.org/A
 // clang-format on
 } // namespace numbers
 
-#pragma GCC diagnostic pop
-
 /// Create a bitmask with the N right-most bits set to 1, and all other
 /// bits set to 0.  Only unsigned types are allowed.
 template <typename T> T maskTrailingOnes(unsigned N) {