[clang] [LifetimeSafety] Add fix-it for misplaced lifetimebound attributes (PR #199149)

[David Meng via cfe-commits]

================
@@ -1,17 +1,24 @@
 // RUN: rm -rf %t
 // RUN: split-file %s %t
 // RUN: %clang_cc1 -fsyntax-only -Wlifetime-safety-cross-tu-misplaced-lifetimebound -Wno-dangling -I%t -verify %t/cross.cpp
+// RUN: %clang_cc1 -fsyntax-only -Wlifetime-safety-cross-tu-misplaced-lifetimebound -Wno-dangling -I%t -fdiagnostics-parseable-fixits %t/cross.cpp 2>&1 | FileCheck %s
+// RUN: %clang_cc1 -Wlifetime-safety-cross-tu-misplaced-lifetimebound -Wno-dangling -I%t -fixit %t/cross.cpp
+// RUN: %clang_cc1 -fsyntax-only -Wlifetime-safety-cross-tu-misplaced-lifetimebound -Wno-dangling -I%t -Werror %t/cross.cpp
 
 //--- cross.h
 struct HeaderObj {
   ~HeaderObj() {}
 };
 
-HeaderObj &header_param(HeaderObj &obj); // expected-warning {{'lifetimebound' attribute on this definition is not visible to callers in other translation units; add it to the declaration instead}}
+HeaderObj &header_param(HeaderObj &  // expected-warning {{'lifetimebound' attribute on this definition is not visible to callers in other translation units; add it to the declaration instead}}
+	obj  // CHECK: fix-it:"{{.*}}cross.h":{[[#]]:{{[0-9]+}}-[[#]]:{{[0-9]+}}}:" {{\[\[}}clang::lifetimebound{{\]\]}}"
+);
 
 struct HeaderS {
   HeaderObj data;
-  HeaderObj &header_this(); // expected-warning {{'lifetimebound' attribute on this definition is not visible to callers in other translation units; add it to the declaration instead}}
+  HeaderObj &header_this(
+  );  // expected-warning {{'lifetimebound' attribute on this definition is not visible to callers in other translation units; add it to the declaration instead}}
+      // CHECK: fix-it:"{{.*}}cross.h":{[[#]]:{{[0-9]+}}-[[#]]:{{[0-9]+}}}:" {{\[\[}}clang::lifetimebound{{\]\]}}"
----------------
davidmenggx wrote:

No, the fix-it would appear on the same line as the warning. 

To be more explicit this could also work:
```cpp
struct HeaderS {
  HeaderObj data;
  HeaderObj &header_this(
  );  // expected-warning {{'lifetimebound' attribute on this definition is not visible to callers in other translation units; add it to the declaration instead}}
      // CHECK: cross.h:[[#WARN_LINE:]]:{{[0-9]+}}: warning: 'lifetimebound' attribute on this definition is not visible
      // CHECK: fix-it:"{{.*}}cross.h":{[[#WARN_LINE]]:{{[0-9]+}}-[[#WARN_LINE]]:{{[0-9]+}}}:" {{\[\[}}clang::lifetimebound{{\]\]}}"
};
```

`@LINE-1` doesn't work here due to the mismatch between the test file's line numbers and `cross.h`'s line numbers

https://github.com/llvm/llvm-project/pull/199149