[clang][Interp] Not all TypeTraitExprs are of bool type

In C, they return an integer, so emit their value as such.

Author: tbaederr

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -1668,7 +1668,9 @@ template <class Emitter>
 bool ByteCodeExprGen<Emitter>::VisitTypeTraitExpr(const TypeTraitExpr *E) {
   if (DiscardResult)
     return true;
-  return this->emitConstBool(E->getValue(), E);
+  if (E->getType()->isBooleanType())
+    return this->emitConstBool(E->getValue(), E);
+  return this->emitConst(E->getValue(), E);
 }
 
 template <class Emitter>

clang/test/Sema/PR2919-builtin-types-compat-strips-crv.c

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -fsyntax-only %s
+// RUN: %clang_cc1 -fsyntax-only %s -fexperimental-new-constant-interpreter
 
 typedef struct foo T0;
 typedef const struct foo T1;

clang/test/Sema/auto-type.c

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 %s -fsyntax-only -Wno-strict-prototypes -verify -pedantic -std=c11
+// RUN: %clang_cc1 %s -fsyntax-only -Wno-strict-prototypes -verify -pedantic -std=c11 -fexperimental-new-constant-interpreter
 
 __auto_type a = 5; // expected-warning {{'__auto_type' is a GNU extension}}
 __extension__ __auto_type a1 = 5;