[CIR][CodeGen] Implemented VisitTypeTraitExpr (#1850)

Implements  Issue #1802

Author: abhijeetsharma200

clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp

@@ -18,6 +18,7 @@
 #include "clang/CIR/MissingFeatures.h"
 
 #include "clang/AST/StmtVisitor.h"
+#include "clang/AST/ExprCXX.h"
 #include "clang/CIR/Dialect/IR/CIRAttrs.h"
 #include "clang/CIR/Dialect/IR/CIRDataLayout.h"
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
@@ -702,7 +703,13 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
     return {};
   }
   mlir::Value VisitTypeTraitExpr(const TypeTraitExpr *E) {
-    llvm_unreachable("NYI");
+    mlir::Location loc = CGF.getLoc(E->getExprLoc());
+    if (E->isStoredAsBoolean())
+      return Builder.getBool(E->getBoolValue(), loc);
+
+    assert(E->getAPValue().isInt() && "APValue type not supported");
+    mlir::Type ty = CGF.convertType(E->getType());
+    return Builder.getConstAPInt(loc, ty, E->getAPValue().getInt());
   }
   mlir::Value
   VisitConceptSpecializationExpr(const ConceptSpecializationExpr *E) {

clang/test/CIR/CodeGen/type-trait.cpp

@@ -0,0 +1,29 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -O2 -fclangir -emit-cir %s -o - | FileCheck %s --check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -O2 -fclangir -emit-llvm %s -o - | FileCheck %s --check-prefix=LLVM
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -O2 -emit-llvm %s -o - | FileCheck %s --check-prefix=LLVM
+
+// CIR-LABEL: cir.func dso_local @_Z4testv() -> !cir.bool
+// CIR:       %[[RETVAL:.+]] = cir.alloca !cir.bool
+// CIR:       %[[CONST_TRUE:.+]] = cir.const #true
+// CIR:       cir.store %[[CONST_TRUE]], %[[RETVAL]]
+// CIR:       %[[LOADED_VAL:.+]] = cir.load %[[RETVAL]]
+// CIR:       cir.return %[[LOADED_VAL]]
+
+// LLVM-LABEL: define dso_local {{.*}}i1 @_Z4testv()
+// LLVM:         ret i1 true
+
+namespace B {
+template <class _0p> class B {
+public:
+  typedef _0p A;
+  B() { __has_trivial_destructor(A); }
+};
+template <class _0p, class _0e0uence = B<_0p>> class A { _0e0uence A; };
+} // namespace B
+
+class A { public: B::A<A> A; };
+
+bool test() {
+  return __has_trivial_destructor(A);
+}
+