[Coroutines] Fix test breakage in D82928

[lxfind]

Summary

The test file in D82928 generated temp files within the test directory, causing test failures. Fix it.

[modocache]

Thanks for the fix!

[thakis]

That's not enough, you also need to add an rm to remove the stale .LL file still on disk, see my comment on your original change.

[lxfind]

In D82986#2126479, @thakis wrote:

That's not enough, you also need to add an rm to remove the stale .LL file still on disk, see my comment on your original change.

It's in https://reviews.llvm.org/D82992 if you could help accept it. Thanks!

clang/test/CoverageMapping/coroutine.cpp

-// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fcoroutines-ts -std=c++14 -emit-llvm -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fcoroutines-ts -std=c++14 -emit-llvm -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping %s -o - | FileCheck %s
 
 namespace std::experimental {
 template <typename... T>
 struct coroutine_traits;
 
 template <class Promise = void>
 struct coroutine_handle {
   coroutine_handle() = default;