[clang-tools-extra] [clang-tidy] modernize-use-nullptr matches "NULL" in templates (PR #109169)

[Thomas Köppe via cfe-commits]

================
@@ -84,6 +84,14 @@ void test_macro_expansion4() {
 #undef MY_NULL
 }
 
+template <typename T> struct pear {
+  T x;
+};
+void test_templated() {
+  pear<int*> p = { NULL };
----------------
tkoeppe wrote:

Done now. A key insight was that the test defines `NULL` as `0`, so in order for the new check to kick in, we're using `__null` as the to-be-diagnosed spelling.

https://github.com/llvm/llvm-project/pull/109169