[clang] [SSAF] Let UnsafeBufferUsageExtractor & PointerFlowExtractor ignore templates (PR #198927)

[Balázs Benics via cfe-commits]

================
@@ -1126,4 +1126,37 @@ TEST_F(PointerFlowTest, NestedLambdaAssign) {
   ASSERT_NE(Sum, nullptr);
   EXPECT_EQ(*Sum, makeEdges(__LINE__, {{{"y", 1U}, {"x", 1U}}}));
 }
+
+//////////////////////////////////////////////////////////////
+//          Template is ignored.                            //
+//////////////////////////////////////////////////////////////
+TEST_F(PointerFlowTest, FunctionTemplate) {
+  ASSERT_EQ(setUpTest(R"cpp(
+    template <typename T>
+    T* f(T *p) {
+      int *q = p
+      return q;
+    }
+  )cpp"),
+            true);
+
+  auto *Sum = getEntitySummary<FunctionDecl>("f");
+
+  ASSERT_EQ(Sum, nullptr);
----------------
steakhal wrote:

Let's keep this lean.

```suggestion
  ASSERT_FALSE(getEntitySummary<FunctionDecl>("f"));
```

https://github.com/llvm/llvm-project/pull/198927