Change a build-attribute REQUIRES check to use supported not requested.

src/IceCompiler.cpp

Index: src/IceCompiler.cpp
diff --git a/src/IceCompiler.cpp b/src/IceCompiler.cpp
index 7c8b791969e63feafdac29b17421876e2640befc..0ef2ffd62014c42bb445f4c1bedebb11e38e4804 100644
--- a/src/IceCompiler.cpp
+++ b/src/IceCompiler.cpp
@@ -47,11 +47,8 @@ struct {
 // Validates values of build attributes. Prints them to Stream if
 // Stream is non-null.
 void ValidateAndGenerateBuildAttributes(const ClFlags &Flags, Ostream *Stream) {
+  // List the supported targets.
   if (Stream) {
-    // List the requested target.
-    *Stream << Flags.getTargetArch() << "\n";
-
-// List the supported targets.
 #define SUBZERO_TARGET(TARGET) *Stream << "target_" #TARGET << "\n";
 #include "llvm/Config/SZTargets.def"
   }