[-Wunsafe-buffer-usage] Emit fixits for arguments of function pointers calls

Currently we ignore calls on function pointers (unlike direct calls of
functions and class methods). This patch adds support for function pointers as
well.

The change is to simply replace use of forEachArgumentWithParam matcher in UPC
gadget with forEachArgumentWithParamType.

from the documentation of forEachArgumentWithParamType:
/// Matches all arguments and their respective types for a \c CallExpr or
/// \c CXXConstructExpr. It is very similar to \c forEachArgumentWithParam but
/// it works on calls through function pointers as well.

Author: jkorous-apple

clang/lib/Analysis/UnsafeBufferUsage.cpp

@@ -281,8 +281,8 @@ isInUnspecifiedPointerContext(internal::Matcher<Stmt> InnerMatcher) {
   //    (i.e., computing the distance between two pointers); or ...
 
   auto CallArgMatcher =
-      callExpr(forEachArgumentWithParam(InnerMatcher,
-                  hasPointerType() /* array also decays to pointer type*/),
+      callExpr(forEachArgumentWithParamType(InnerMatcher,
+                  isAnyPointer() /* array also decays to pointer type*/),
           unless(callee(functionDecl(hasAttr(attr::UnsafeBufferUsage)))));
 
   auto CastOperandMatcher =

clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-pointer-arg-to-func-ptr-call.cpp

@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -std=c++20 -Wunsafe-buffer-usage \
+// RUN:            -fsafe-buffer-usage-suggestions \
+// RUN:            -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
+
+void unsafe_array_func_ptr_call(void (*fn_ptr)(int *param)) {
+  int p[32];
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::array<int, 32> p"
+
+  int tmp = p[5];
+  fn_ptr(p);
+  // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:11-[[@LINE-1]]:11}:".data()"
+}