Emit the SubRegTable with the smallest possible integer type.

Doesn't help ARM with its massive register set, but halves the size on x86 and all other targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151760 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenTarget.cpp b/utils/TableGen/CodeGenTarget.cpp
index cf67935..1eb1a54 100644
--- a/utils/TableGen/CodeGenTarget.cpp
+++ b/utils/TableGen/CodeGenTarget.cpp
@@ -108,6 +108,14 @@
   return Namespace + "::" + R->getName();
 }
 
+const char *llvm::getMinimalTypeForRange(uint64_t Range) {
+  assert(Range < 0xFFFFFFFFULL && "Enum too large");
+  if (Range > 0xFFFF)
+    return "uint32_t";
+  if (Range > 0xFF)
+    return "uint16_t";
+  return "uint8_t";
+}
 
 /// getTarget - Return the current instance of the Target class.
 ///