Remove the ASTContext parameter from the attribute-related methods of Decl.
The implementations of these methods can Use Decl::getASTContext() to get the ASTContext.

This commit touches a lot of files since call sites for these methods are everywhere.
I used pre-tokenized "carbon.h" and "cocoa.h" headers to do some timings, and there was no real time difference between before the commit and after it.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74501 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHReaderDecl.cpp b/lib/Frontend/PCHReaderDecl.cpp
index 3f6ae35..15b54a2 100644
--- a/lib/Frontend/PCHReaderDecl.cpp
+++ b/lib/Frontend/PCHReaderDecl.cpp
@@ -80,7 +80,7 @@
   D->setLocation(SourceLocation::getFromRawEncoding(Record[Idx++]));
   D->setInvalidDecl(Record[Idx++]);
   if (Record[Idx++])
-    D->addAttr(*Reader.getContext(), Reader.ReadAttributes());
+    D->addAttr(Reader.ReadAttributes());
   D->setImplicit(Record[Idx++]);
   D->setUsed(Record[Idx++]);
   D->setAccess((AccessSpecifier)Record[Idx++]);