src/base/debug/stack_trace_posix.cc: suppressed unused function warnings
for functions DemangleSymbols, OutputPointer(in order to compile with
-Werror flag)

test/cctest/test-isolate-independent-builtins.cc: corrections to make
ByteInText test case compatible with aix. (affects aix only)

Change-Id: I49e45e63545404c77aaed3f51b26557f6f03455e
Reviewed-on: https://chromium-review.googlesource.com/927484Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52071}