Add a basic TargetARM32 skeleton which knows nothing.

src/IceCompiler.cpp

 //===- subzero/src/IceCompiler.cpp - Driver for bitcode translation -------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines a driver for translating PNaCl bitcode into native code.
@@ skipping 29 matching lines @@
                                   {"disable_ir_gen", ALLOW_DISABLE_IR_GEN},
                                   {"llvm_cl", ALLOW_LLVM_CL},
                                   {"llvm_ir", ALLOW_LLVM_IR},
                                   {"llvm_ir_as_input", ALLOW_LLVM_IR_AS_INPUT},
                                   {"minimal_build", ALLOW_MINIMAL_BUILD},
                                   {"browser_mode", PNACL_BROWSER_TRANSLATOR}};
 
 // Validates values of build attributes. Prints them to Stream if
 // Stream is non-null.
 void ValidateAndGenerateBuildAttributes(const ClFlags &Flags, Ostream *Stream) {
-  if (Stream)
+  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"
+  }
+
   for (size_t i = 0; i < llvm::array_lengthof(ConditionalBuildAttributes);
        ++i) {
     switch (ConditionalBuildAttributes[i].FlagValue) {
     case 0:
       if (Stream)
         *Stream << "no_" << ConditionalBuildAttributes[i].FlagName << "\n";
       break;
     case 1:
       if (Stream)
         *Stream << "allow_" << ConditionalBuildAttributes[i].FlagName << "\n";
@@ skipping 92 matching lines @@
     Ctx.dumpTimers();
   if (Ctx.getFlags().getTimeEachFunction()) {
     const bool DumpCumulative = false;
     Ctx.dumpTimers(GlobalContext::TSK_Funcs, DumpCumulative);
   }
   const bool FinalStats = true;
   Ctx.dumpStats("_FINAL_", FinalStats);
 }
 
 } // end of namespace Ice