Revert "[Clang,Driver] Add -fveclib=Darwin_libsystem_m support."

This reverts commit 187a14e.

The test added in this commit is failing on several build bots:

https://lab.llvm.org/buildbot/#/builders/139/builds/4059
https://lab.llvm.org/buildbot/#/builders/132/builds/5605

Author: dyung

clang/include/clang/Basic/CodeGenOptions.h

@@ -55,12 +55,11 @@ class CodeGenOptions : public CodeGenOptionsBase {
   };
 
   enum VectorLibrary {
-    NoLibrary,         // Don't use any vector library.
-    Accelerate,        // Use the Accelerate framework.
-    LIBMVEC,           // GLIBC vector math library.
-    MASSV,             // IBM MASS vector library.
-    SVML,              // Intel short vector math library.
-    Darwin_libsystem_m // Use Darwin's libsytem_m vector functions.
+    NoLibrary,  // Don't use any vector library.
+    Accelerate, // Use the Accelerate framework.
+    LIBMVEC,    // GLIBC vector math library.
+    MASSV,      // IBM MASS vector library.
+    SVML        // Intel short vector math library.
   };
 
   enum ObjCDispatchMethodKind {

clang/include/clang/Driver/Options.td

@@ -2171,10 +2171,9 @@ def fno_experimental_isel : Flag<["-"], "fno-experimental-isel">, Group<f_clang_
   Alias<fno_global_isel>;
 def fveclib : Joined<["-"], "fveclib=">, Group<f_Group>, Flags<[CC1Option]>,
     HelpText<"Use the given vector functions library">,
-    Values<"Accelerate,libmvec,MASSV,SVML,Darwin_libsystem_m,none">,
+    Values<"Accelerate,libmvec,MASSV,SVML,none">,
     NormalizedValuesScope<"CodeGenOptions">,
-    NormalizedValues<["Accelerate", "LIBMVEC", "MASSV", "SVML",
-                      "Darwin_libsystem_m", "NoLibrary"]>,
+    NormalizedValues<["Accelerate", "LIBMVEC", "MASSV", "SVML", "NoLibrary"]>,
     MarshallingInfoEnum<CodeGenOpts<"VecLib">, "NoLibrary">;
 def fno_lax_vector_conversions : Flag<["-"], "fno-lax-vector-conversions">, Group<f_Group>,
   Alias<flax_vector_conversions_EQ>, AliasArgs<["none"]>;

clang/lib/CodeGen/BackendUtil.cpp

@@ -402,10 +402,6 @@ static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
   case CodeGenOptions::SVML:
     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
     break;
-  case CodeGenOptions::Darwin_libsystem_m:
-    TLII->addVectorizableFunctionsFromVecLib(
-        TargetLibraryInfoImpl::DarwinLibSystemM);
-    break;
   default:
     break;
   }

clang/test/CodeGen/veclib-darwin-libsystem-m.c

@@ -76,7 +76,6 @@
 // FLTOALL-NEXT: thin
 // RUN: %clang --autocomplete=-fveclib= | FileCheck %s -check-prefix=FVECLIBALL
 // FVECLIBALL: Accelerate
-// FVECLIBALL-NEXT: Darwin_libsystem_m
 // FVECLIBALL-NEXT: libmvec
 // FVECLIBALL-NEXT: MASSV
 // FVECLIBALL-NEXT: none

clang/test/Driver/autocomplete.c

@@ -2,14 +2,12 @@
 // RUN: %clang -### -c -fveclib=Accelerate %s 2>&1 | FileCheck -check-prefix CHECK-ACCELERATE %s
 // RUN: %clang -### -c -fveclib=libmvec %s 2>&1 | FileCheck -check-prefix CHECK-libmvec %s
 // RUN: %clang -### -c -fveclib=MASSV %s 2>&1 | FileCheck -check-prefix CHECK-MASSV %s
-// RUN: %clang -### -c -fveclib=Darwin_libsystem_m %s 2>&1 | FileCheck -check-prefix CHECK-DARWIN_LIBSYSTEM_M %s
 // RUN: not %clang -c -fveclib=something %s 2>&1 | FileCheck -check-prefix CHECK-INVALID %s
 
 // CHECK-NOLIB: "-fveclib=none"
 // CHECK-ACCELERATE: "-fveclib=Accelerate"
 // CHECK-libmvec: "-fveclib=libmvec"
 // CHECK-MASSV: "-fveclib=MASSV"
-// CHECK-DARWIN_LIBSYSTEM_M: "-fveclib=Darwin_libsystem_m"
 
 // CHECK-INVALID: error: invalid value 'something' in '-fveclib=something'