Fix integer comparison in DIEInteger::BestForm.

The always-true "(int)Int == (signed)Int" comparison was found
while experimenting with a potential new Clang warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177290 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DIE.h b/lib/CodeGen/AsmPrinter/DIE.h
index 9907b01..d087c54 100644
--- a/lib/CodeGen/AsmPrinter/DIE.h
+++ b/lib/CodeGen/AsmPrinter/DIE.h
@@ -235,9 +235,10 @@
     ///
     static unsigned BestForm(bool IsSigned, uint64_t Int) {
       if (IsSigned) {
-        if ((char)Int == (signed)Int)   return dwarf::DW_FORM_data1;
-        if ((short)Int == (signed)Int)  return dwarf::DW_FORM_data2;
-        if ((int)Int == (signed)Int)    return dwarf::DW_FORM_data4;
+        const int64_t SignedInt = Int;
+        if ((char)Int == SignedInt)     return dwarf::DW_FORM_data1;
+        if ((short)Int == SignedInt)    return dwarf::DW_FORM_data2;
+        if ((int)Int == SignedInt)      return dwarf::DW_FORM_data4;
       } else {
         if ((unsigned char)Int == Int)  return dwarf::DW_FORM_data1;
         if ((unsigned short)Int == Int) return dwarf::DW_FORM_data2;