[clang] Temporarily silence noisy warning for FPEvalMethod

See #137600 (comment)

Author: nico

clang/include/clang/Basic/LangOptions.def

@@ -347,7 +347,17 @@ BENIGN_ENUM_LANGOPT(DefaultFPContractMode, FPModeKind, 2, FPM_Off, "FP contracti
 COMPATIBLE_LANGOPT(ExpStrictFP, 1, false, "Enable experimental strict floating point")
 BENIGN_LANGOPT(RoundingMath, 1, false, "Do not assume default floating-point rounding behavior")
 BENIGN_ENUM_LANGOPT(FPExceptionMode, FPExceptionModeKind, 2, FPE_Default, "FP Exception Behavior Mode type")
+
+#if defined(__clang__)
+// FIXME: Remove this once the warning is fixed, https://llvm.org/PR137600
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wpreferred-type-bitfield-enum-conversion"
+#endif
 BENIGN_ENUM_LANGOPT(FPEvalMethod, FPEvalMethodKind, 3, FEM_UnsetOnCommandLine, "FP type used for floating point arithmetic")
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
 ENUM_LANGOPT(Float16ExcessPrecision, ExcessPrecisionKind, 2, FPP_Standard, "Intermediate truncation behavior for Float16 arithmetic")
 ENUM_LANGOPT(BFloat16ExcessPrecision, ExcessPrecisionKind, 2, FPP_Standard, "Intermediate truncation behavior for BFloat16 arithmetic")
 LANGOPT(NoBitFieldTypeAlign , 1, 0, "bit-field type alignment")