added c17 tests

Author: Aidan

clang/test/Sema/nullptr-prec2x.c

@@ -6,3 +6,7 @@ int nullptr; // expected-warning {{'nullptr' is a keyword in C23}}
 
 nullptr_t val; // expected-error {{unknown type name 'nullptr_t'}}
 
+void foo(void *);
+void bar() { foo(__nullptr); } // Test that it converts properly to an arbitrary pointer type without warning
+_Static_assert(__nullptr == 0, "value of __nullptr"); // Test that its value matches that of NULL
+_Static_assert(_Generic(__typeof(__nullptr), int : 0, void * : 0, default : 1), "type of __nullptr"); // Test that it's type is not the same as what NULL would generally have.

clang/test/Sema/nullptr.c

@@ -113,5 +113,3 @@ void foo(void *);
 void bar() { foo(__nullptr); }
 static_assert(nullptr == __nullptr);
 static_assert(_Generic(typeof(__nullptr), nullptr_t: true, default: false));
-_Static_assert(__nullptr == 0); // Test that its value matches that of NULL
-_Static_assert(_Generic(__typeof(__nullptr), int : 0, void * : 0, default : 1)); // Test that it's type is not the same as what NULL would generally have.