[powerpc] deactivate readability-identifier-naming.cpp test on powerpc64le

The test case clang-tidy/readability-identifier-naming.cpp segfaults on
powerpc64 little endian (starting with r288563) when a bootstrap build/test
is done.  To get the buildbot running again deactivate the test.
When the issue is resolved reactivate it.

llvm-svn: 289581

clang-tools-extra/test/clang-tidy/readability-identifier-naming.cpp

@@ -1,3 +1,6 @@
+// Remove UNSUPPORTED for powerpc64le when the problem introduced by
+// r288563 is resolved.
+// UNSUPPORTED: powerpc64le
 // RUN: %check_clang_tidy %s readability-identifier-naming %t -- \
 // RUN:   -config='{CheckOptions: [ \
 // RUN:     {key: readability-identifier-naming.AbstractClassCase, value: CamelCase}, \