[clang][driver] Disable non-functional --version option for clang -cc1

This patch removes --version as a clang -cc1 option.
  clang --version
and
  clang --cc1 -version
remain valid. This behaviour is consistent with clang -cc1as.

Previously, clang -cc1 accepted both --version and -version, but
only -version was acted upon. The call
  clang -cc1 --version
stalled without any message: --version was an accepted option but
triggered no action, and the driver waited for standard input.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D122344

clang/include/clang/Driver/Options.td

@@ -4203,7 +4203,7 @@ def _serialize_diags : Separate<["-", "--"], "serialize-diagnostics">, Flags<[No
   HelpText<"Serialize compiler diagnostics to a file">;
 // We give --version different semantics from -version.
 def _version : Flag<["--"], "version">,
-  Flags<[CoreOption, CC1Option, FC1Option, FlangOption]>,
+  Flags<[CoreOption, FC1Option, FlangOption]>,
   HelpText<"Print version information">;
 def _signed_char : Flag<["--"], "signed-char">, Alias<fsigned_char>;
 def _std : Separate<["--"], "std">, Alias<std_EQ>;

clang/test/Frontend/unknown-arg.c

@@ -4,6 +4,9 @@
 // RUN: FileCheck %s --check-prefix=DID-YOU-MEAN
 // RUN: not %clang %s -E -Xclang --hel[ 2>&1 | \
 // RUN: FileCheck %s --check-prefix=DID-YOU-MEAN
+// RUN: not %clang_cc1 --version 2>&1 | \
+// RUN: FileCheck %s --check-prefix=DID-YOU-MEAN-VER
 
 // CHECK: error: unknown argument: '--helium'
 // DID-YOU-MEAN: error: unknown argument '--hel['; did you mean '--help'?
+// DID-YOU-MEAN-VER: error: unknown argument '--version'; did you mean '-version'?