[clang] blacklist `--expt-relaxed-constexpr`

Summary: Unsupported flag is unsupported.

Reviewed By: dulmarod

Differential Revision: D6773101

fbshipit-source-id: 8167b6e

infer/src/clang/ClangCommand.ml

@@ -13,7 +13,9 @@ module L = Logging
 type t = {exec: string; argv: string list; orig_argv: string list; quoting_style: ClangQuotes.style}
 
 (** bad for every clang invocation *)
-let clang_blacklisted_flags = ["-fembed-bitcode-marker"; "-fno-canonical-system-headers"]
+let clang_blacklisted_flags =
+  ["--expt-relaxed-constexpr"; "-fembed-bitcode-marker"; "-fno-canonical-system-headers"]
+
 
 let fcp_dir =
   Config.bin_dir ^/ Filename.parent_dir_name ^/ Filename.parent_dir_name