treat bool literals as constatnt expressions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55255 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index b004bde..5107a56 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -720,6 +720,13 @@
     Result.setIsUnsigned(!getType()->isSignedIntegerType());
     break;
   }
+  case CXXBoolLiteralExprClass: {
+    const CXXBoolLiteralExpr *BL = cast<CXXBoolLiteralExpr>(this);
+    Result.zextOrTrunc(static_cast<uint32_t>(Ctx.getTypeSize(getType())));
+    Result = BL->getValue();
+    Result.setIsUnsigned(!getType()->isSignedIntegerType());
+    break;
+  }
   case CXXZeroInitValueExprClass:
     Result.clear();
     break;