[wpiutil] Upgrade to LLVM 18.1.1 (#6405)

wpiutil/src/main/native/thirdparty/llvm/include/wpi/Compiler.h

@@ -162,6 +162,25 @@
 #define LLVM_DEPRECATED(MSG, FIX) [[deprecated(MSG)]]
 #endif
 
+// clang-format off
+#if defined(__clang__) || defined(__GNUC__)
+#define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_PUSH                             \
+  _Pragma("GCC diagnostic push")                                               \
+  _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
+#define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_POP                              \
+  _Pragma("GCC diagnostic pop")
+#elif defined(_MSC_VER)
+#define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_PUSH                             \
+  _Pragma("warning(push)")                                                     \
+  _Pragma("warning(disable : 4996)")
+#define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_POP                              \
+  _Pragma("warning(pop)")
+#else
+#define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_PUSH
+#define LLVM_SUPPRESS_DEPRECATED_DECLARATIONS_POP
+#endif
+// clang-format on
+
 // Indicate that a non-static, non-const C++ member function reinitializes
 // the entire object to a known state, independent of the previous state of
 // the object.
@@ -330,6 +349,12 @@
 #define LLVM_GSL_POINTER
 #endif
 
+#if LLVM_HAS_CPP_ATTRIBUTE(nodiscard) >= 201907L
+#define LLVM_CTOR_NODISCARD [[nodiscard]]
+#else
+#define LLVM_CTOR_NODISCARD
+#endif
+
 /// LLVM_EXTENSION - Support compilers where we have a keyword to suppress
 /// pedantic diagnostics.
 #ifndef LLVM_EXTENSION
@@ -598,4 +623,12 @@ void AnnotateIgnoreWritesEnd(const char *file, int line);
 #define LLVM_NO_PROFILE_INSTRUMENT_FUNCTION
 #endif
 
+/// \macro LLVM_PREFERRED_TYPE
+/// Adjust type of bit-field in debug info.
+#if __has_attribute(preferred_type)
+#define LLVM_PREFERRED_TYPE(T) __attribute__((preferred_type(T)))
+#else
+#define LLVM_PREFERRED_TYPE(T)
+#endif
+
 #endif