Add support for System z vector language extensions

The z13 vector facility has an associated language extension,
closely modeled on AltiVec/VSX.  The main differences are:

- vector long, vector float and vector pixel are not supported

- vector long long and vector double are supported (like VSX)

- comparison operators return a vector rather than a scalar integer

- shift operators behave like the OpenCL shift operators

- vector bool is only supported as argument to certain operators;
  some operators allow mixing a bool with a non-bool vector 

This patch adds clang support for the extension.  It is closely modelled
on the AltiVec support.  Similarly to the -faltivec option, there's a
new -fzvector option to enable the extensions (as well as an -mzvector
alias for compatibility with GCC).  There's also a separate LangOpt.

The extension as implemented here is intended to be compatible with
the -mzvector extension recently implemented by GCC.

Based on a patch by Richard Sandiford.

Differential Revision: http://reviews.llvm.org/D11001

llvm-svn: 243642
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index d80443b..4dbc541 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -4053,9 +4053,11 @@
   if (Args.hasFlag(options::OPT_femulated_tls, options::OPT_fno_emulated_tls,
                    EmulatedTLSDefault))
     CmdArgs.push_back("-femulated-tls");
-  // AltiVec language extensions aren't relevant for assembling.
-  if (!isa<PreprocessJobAction>(JA) || Output.getType() != types::TY_PP_Asm)
+  // AltiVec-like language extensions aren't relevant for assembling.
+  if (!isa<PreprocessJobAction>(JA) || Output.getType() != types::TY_PP_Asm) {
     Args.AddLastArg(CmdArgs, options::OPT_faltivec);
+    Args.AddLastArg(CmdArgs, options::OPT_fzvector);
+  }
   Args.AddLastArg(CmdArgs, options::OPT_fdiagnostics_show_template_tree);
   Args.AddLastArg(CmdArgs, options::OPT_fno_elide_type);
 
@@ -4100,6 +4102,12 @@
                                                        << "ppc/ppc64/ppc64le";
   }
 
+  // -fzvector is incompatible with -faltivec.
+  if (Arg *A = Args.getLastArg(options::OPT_fzvector))
+    if (Args.hasArg(options::OPT_faltivec))
+      D.Diag(diag::err_drv_argument_not_allowed_with) << A->getAsString(Args)
+                                                      << "-faltivec";
+
   if (getToolChain().SupportsProfiling())
     Args.AddLastArg(CmdArgs, options::OPT_pg);