Recommit r292214 "[Support/Compression] - Change zlib API to return Error instead of custom status"

No any changes, will follow up with D28807 commit containing APLi change for clang
to fix build issues happened.

Original commit message:
[Support/Compression] - Change zlib API to return Error instead of custom status.

Previously API returned custom enum values.
Patch changes it to return Error with string description.
That should help users to report errors in universal way.

Differential revision: https://reviews.llvm.org/D28684

llvm-svn: 292226
diff --git a/llvm/lib/Object/Decompressor.cpp b/llvm/lib/Object/Decompressor.cpp
index bca41fd..0be602b 100644
--- a/llvm/lib/Object/Decompressor.cpp
+++ b/llvm/lib/Object/Decompressor.cpp
@@ -95,8 +95,5 @@
 
 Error Decompressor::decompress(MutableArrayRef<char> Buffer) {
   size_t Size = Buffer.size();
-  zlib::Status Status = zlib::uncompress(SectionData, Buffer.data(), Size);
-  if (Status != zlib::StatusOK)
-    return createError("decompression failed");
-  return Error::success();
+  return zlib::uncompress(SectionData, Buffer.data(), Size);
 }