Sema: Preserve attributes on parameters in instantiated function templates.

This was causing correctness issues for ARC and the static analyzer when a
function template has "consumed" Objective-C object parameters (i.e.
parameters that will be released by the function before returning).

The fix is threefold:
(1) Actually copy over the attributes from old ParmVarDecls to new ones.
(2) Have Sema::BuildFunctionType only work for building FunctionProtoTypes,
    which it was doing anyway. This allows us to pass an ExtProtoInfo
    instead of a plain ExtInfo and several flags.
(3) Drop param attributes as part of StripImplicitInstantiation, which is
    used when an implicit instantiation is followed by an explicit one.

<rdar://problem/12685622>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176728 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index c479895..f3bbe8a 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -2418,13 +2418,9 @@
 
   if (FunctionType) {
     *FunctionType = BuildFunctionType(ResultType, ParamTypes,
-                                      Proto->isVariadic(),
-                                      Proto->hasTrailingReturn(),
-                                      Proto->getTypeQuals(),
-                                      Proto->getRefQualifier(),
                                       Function->getLocation(),
                                       Function->getDeclName(),
-                                      Proto->getExtInfo());
+                                      Proto->getExtProtoInfo());
     if (FunctionType->isNull() || Trap.hasErrorOccurred())
       return TDK_SubstitutionFailure;
   }