[clang][test] Write temporary files to %t

The issue was introduced in
3a9ef4e.

Author: gribozavr

clang/test/CodeGenCoroutines/coro-elide-thinlto.cpp

@@ -3,10 +3,10 @@
 // This test is adapted from coro-elide.cpp and splits functions into two files.
 //
 // RUN: split-file %s %t
-// RUN: %clang --target=x86_64-linux -std=c++20 -O2 -flto=thin -I %S -c %t/coro-elide-callee.cpp -o coro-elide-callee.bc
-// RUN: %clang --target=x86_64-linux -std=c++20 -O2 -flto=thin -I %S -c %t/coro-elide-caller.cpp -o coro-elide-caller.bc
-// RUN: llvm-lto --thinlto coro-elide-callee.bc coro-elide-caller.bc -o summary
-// RUN: %clang_cc1 -O2 -x ir coro-elide-caller.bc -fthinlto-index=summary.thinlto.bc -emit-llvm -o - | FileCheck %s
+// RUN: %clang --target=x86_64-linux -std=c++20 -O2 -flto=thin -I %S -c %t/coro-elide-callee.cpp -o %t/coro-elide-callee.bc
+// RUN: %clang --target=x86_64-linux -std=c++20 -O2 -flto=thin -I %S -c %t/coro-elide-caller.cpp -o %t/coro-elide-caller.bc
+// RUN: llvm-lto --thinlto %t/coro-elide-callee.bc %t/coro-elide-caller.bc -o %t/summary
+// RUN: %clang_cc1 -O2 -x ir %t/coro-elide-caller.bc -fthinlto-index=%t/summary.thinlto.bc -emit-llvm -o - | FileCheck %s
 
 //--- coro-elide-task.h
 #pragma once