Optimize Declarator to avoid malloc/free traffic for the argument list of a
function DeclaratorChunk in common cases.  This uses a fixed array in 
Declarator when it is small enough for the first function declarator chunk
in a declarator.

This eliminates all malloc/free traffic from DeclaratorChunk::getFunction
when running on Cocoa.h except for five functions: signal/bsd_signal/sigset,
which have multiple Function DeclChunk's, and 
CFUUIDCreateWithBytes/CFUUIDGetConstantUUIDWithBytes, which take more than
16 arguments.

This patch was pair programmed with Steve.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62599 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 6f731ca..c91d174 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2772,7 +2772,7 @@
   Error = Error; // Silence warning.
   assert(!Error && "Error setting up implicit decl!");
   Declarator D(DS, Declarator::BlockContext);
-  D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc));
+  D.AddTypeInfo(DeclaratorChunk::getFunction(false, false, 0, 0, 0, Loc, D));
   D.SetIdentifier(&II, Loc);
   
   // Insert this function into translation-unit scope.