Fix hidden-redecls.m test for some environments

[kschwarz]

Summary

This test was failing in our CI environment, because Jenkins mounts the workspaces into Docker containers using their full path, i.e. /home/jenkins/workspaces/llvm-build.
We've seen permission denied errors because /home/jenkins is mounted with root permissions and the default cache directory under Linux is $HOME/.cache.

The fix is to explicitly provide the -fmodules-cache-path, which the other tests already seem to provide.

[akyrtzi]

Thank you! Are you able to commit it by yourself?

[kschwarz]

Yes, I'll commit it tomorrow, thanks for the review @akyrtzi!

clang/test/Index/hidden-redecls.m

 @import hidden_redecls;
 
 @interface Foo (Top)
 - (void)top_method;
 @end
 
 // p1_method in protocol P1 is hidden since module_redecls.sub hasn't been
 // imported yet. Check it is still indexed.
 
-// RUN: c-index-test -index-file-full %s -isystem %S/Inputs -fmodules -target x86_64-apple-macosx10.7 | FileCheck %s
+// RUN: rm -rf %t
+// RUN: c-index-test -index-file-full %s -isystem %S/Inputs -fmodules -fmodules-cache-path=%t -target x86_64-apple-macosx10.7 | FileCheck %s
 // CHECK: [indexDeclaration]: kind: objc-instance-method | name: p1_method | {{.*}} | loc: {{.*}}hidden-redecls-sub.h:2:9 | {{.*}} | isRedecl: 0
 // CHECK: [indexDeclaration]: kind: objc-instance-method | name: p1_method | {{.*}} | loc: {{.*}}hidden-redecls-sub.h:3:9 | {{.*}} | isRedecl: 1