Support for -Wa,-compress-debug-sections.

Also, while I'm here, support -nocompress-debug-sections too.

llvm-svn: 204959
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index d744865..b9706e8 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -447,6 +447,7 @@
   Opts.InstrumentFunctions = Args.hasArg(OPT_finstrument_functions);
   Opts.InstrumentForProfiling = Args.hasArg(OPT_pg);
   Opts.EmitOpenCLArgMetadata = Args.hasArg(OPT_cl_kernel_arg_info);
+  Opts.CompressDebugSections = Args.hasArg(OPT_compress_debug_sections);
   Opts.DebugCompilationDir = Args.getLastArgValue(OPT_fdebug_compilation_dir);
   Opts.LinkBitcodeFile = Args.getLastArgValue(OPT_mlink_bitcode_file);
   Opts.SanitizerBlacklistFile = Args.getLastArgValue(OPT_fsanitize_blacklist);