[clang] [LifetimeSafety] Add fixit verification with FileCheck (PR #180488)

[Baranov Victor via cfe-commits]

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@@ -0,0 +1,139 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++17 -flifetime-safety-inference \
+// RUN:   -fexperimental-lifetime-safety-tu-analysis \
+// RUN:   -Wlifetime-safety-suggestions -Wno-dangling \
+// RUN:   -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
+
+struct View;
+
+struct [[gsl::Owner]] MyObj {
+  int id;
+  MyObj(int i) : id(i) {}
+  MyObj() {}
+  ~MyObj() {}
+  MyObj operator+(MyObj);
+  View getView() const [[clang::lifetimebound]];
+};
+
+struct [[gsl::Pointer()]] View {
+  View(const MyObj &);
+  View();
+  void use() const;
+};
+
+View return_view(View a) {
+  // CHECK: :[[@LINE-1]]:18: warning: parameter in intra-TU function should be marked {{\[\[}}clang::lifetimebound]] [-Wlifetime-safety-intra-tu-suggestions]
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vbvictor wrote:

> I think it might be sufficient to only match on the full diagnostics once and just match a prefix for the rest

Yeah, I removed long lines but fixes remained as is.

https://github.com/llvm/llvm-project/pull/180488