Revert "[AIX][tests] XFAIL -ftime-trace test for now"

The test was fixed by 2f99932.

This reverts commit 25dc215.

Author: jakeegan

clang/test/Driver/ftime-trace.cpp

@@ -1,6 +1,3 @@
-// Failing on AIX due to D150282
-// XFAIL: target={{.*}}-aix{{.*}}
-
 // RUN: rm -rf %t && mkdir -p %t && cd %t
 // RUN: %clangxx -S -no-canonical-prefixes -ftime-trace -ftime-trace-granularity=0 -o out %s
 // RUN: cat out.json \