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

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

llvm-svn: 204959
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index eee3292..17f5f4d6 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -443,6 +443,9 @@
   if (CodeGenOpts.DisableIntegratedAS)
     Options.DisableIntegratedAS = true;
 
+  if (CodeGenOpts.CompressDebugSections)
+    Options.CompressDebugSections = true;
+
   // Set frame pointer elimination mode.
   if (!CodeGenOpts.DisableFPElim) {
     Options.NoFramePointerElim = false;