[driver] Add the -ftree-vectorize flag as a alias of -fvectorize to maintain

compatibility with gcc.
rdar://12839978 

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169888 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Driver/Options.td

@@ -653,6 +653,8 @@ def ftest_coverage : Flag<["-"], "ftest-coverage">, Group<f_Group>;
 def fvectorize : Flag<["-"], "fvectorize">, Group<f_Group>,
   HelpText<"Enable the loop vectorization passes">;
 def fno_vectorize : Flag<["-"], "fno-vectorize">, Group<f_Group>;
+def ftree_vectorize : Flag<["-"], "ftree-vectorize">, Alias<fvectorize>;
+def fno_tree_vectorize : Flag<["-"], "fno-tree-vectorize">, Alias<fno_vectorize>;
 def Wlarge_by_value_copy_def : Flag<["-"], "Wlarge-by-value-copy">,
   HelpText<"Warn if a function definition returns or accepts an object larger "
            "in bytes than a given value">, Flags<[HelpHidden]>;

test/Driver/clang_f_opts.c

@@ -43,6 +43,10 @@
 // RUN: %clang -### -S -fno-vectorize -fvectorize %s 2>&1 | FileCheck -check-prefix=CHECK-VECTORIZE %s
 // RUN: %clang -### -S -fno-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-NO-VECTORIZE %s
 // RUN: %clang -### -S -fvectorize -fno-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-NO-VECTORIZE %s
+// RUN: %clang -### -S -ftree-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-VECTORIZE %s
+// RUN: %clang -### -S -ftree-no-vectorize -fvectorize %s 2>&1 | FileCheck -check-prefix=CHECK-VECTORIZE %s
+// RUN: %clang -### -S -ftree-no-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-NO-VECTORIZE %s
+// RUN: %clang -### -S -ftree-vectorize -fno-vectorize %s 2>&1 | FileCheck -check-prefix=CHECK-NO-VECTORIZE %s
 // CHECK-VECTORIZE: "-backend-option"
 // CHECK-VECTORIZE: "-vectorize-loops"
 // CHECK-NO-VECTORIZE-NOT: "-backend-option"