Keep existing tests but update expected errors and warnings

Author: imdj

clang/test/CXX/expr/expr.prim/expr.prim.req/nested-requirement.cpp

@@ -37,6 +37,21 @@ namespace std_example {
   static_assert(D<T1>);
   template<D T> struct D_check {}; // expected-note{{because 'short' does not satisfy 'D'}}
   using dc1 = D_check<short>; // expected-error{{constraints not satisfied for class template 'D_check' [with T = short]}}
+
+  template<typename T>
+  concept C2 = requires (T a) {
+      requires sizeof(a) == 4; // OK
+      requires a == 0; // expected-error{{substitution into constraint expression resulted in a non-constant expression}}
+      // expected-note@-1{{while checking the satisfaction of nested requirement requested here}}
+      // expected-note@-2{{in instantiation of requirement here}}
+      // expected-note@-3{{while checking the satisfaction of nested requirement requested here}}
+      // expected-note@-6{{while substituting template arguments into constraint expression here}}
+      // expected-note@-5{{function parameter 'a' with unknown value cannot be used in a constant expression}}
+      // expected-note@-8{{declared here}}
+    };
+    static_assert(C2<int>); // expected-error{{static assertion failed}}
+    // expected-note@-1{{while checking the satisfaction of concept 'C2<int>' requested here}}
+    // expected-note@-2{{because 'int' does not satisfy 'C2'}}
 }
 
 template<typename T>

clang/test/CXX/expr/expr.prim/expr.prim.req/simple-requirement.cpp

@@ -98,6 +98,15 @@ namespace std_example {
   using c1c2 = C_check<int *>; // expected-error{{constraints not satisfied for class template 'C_check' [with T = int *]}}
 }
 
+// typeid() of an expression becomes potentially evaluated if the expression is
+// of a polymorphic type.
+class X { virtual ~X(); };
+constexpr bool b = requires (X &x) { static_cast<int(*)[(typeid(x), 0)]>(nullptr); };
+// expected-warning@-1 {{left operand of comma operator has no effect}}
+// expected-warning@-2 {{variable length arrays in C++ are a Clang extension}}
+// expected-note@-3{{function parameter 'x' with unknown value cannot be used in a constant expression}}
+// expected-note@-4{{declared here}}
+
 namespace access_checks {
 namespace in_requires_expression {
 template<auto>