Allow conditional lit tests in Subzero, based on build flags.

src/IceTypes.cpp

Index: src/IceTypes.cpp
diff --git a/src/IceTypes.cpp b/src/IceTypes.cpp
index 6b81d8ac9e8765aef9dee0736bbcee4972373e8a..7155baa48dce3d517f867d1876c4589b645af9d8 100644
--- a/src/IceTypes.cpp
+++ b/src/IceTypes.cpp
@@ -18,6 +18,12 @@ namespace Ice {
 
 namespace {
 
+const char *TargetArchName[] = {
+#define X(tag, str)  str ,
+  TARGETARCH_TABLE
+#undef X
+};
+
 // Show tags match between ICETYPE_TABLE and ICETYPE_PROPS_TABLE.
 
 // Define a temporary set of enum values based on ICETYPE_TABLE
@@ -116,6 +122,14 @@ const TypePropertyFields TypePropertiesTable[] = {
 
 } // end anonymous namespace
 
+const char *targetArchString(const TargetArch Arch) {
+  size_t Index = static_cast<size_t>(Arch);
+  if (Index < TargetArch_NUM)
+    return TargetArchName[Index];
+  llvm_unreachable("Invalid target arch for targetArchString");
+  return "???";
+}
+
 size_t typeWidthInBytes(Type Ty) {
   size_t Index = static_cast<size_t>(Ty);
   if (Index < IceType_NUM)