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>

llvm-svn: 176728
diff --git a/clang/test/SemaObjCXX/arc-nsconsumed-errors.mm b/clang/test/SemaObjCXX/arc-nsconsumed-errors.mm
index 93f5d99..10ae10d 100644
--- a/clang/test/SemaObjCXX/arc-nsconsumed-errors.mm
+++ b/clang/test/SemaObjCXX/arc-nsconsumed-errors.mm
@@ -18,3 +18,35 @@
 blk1 c3 = ^void (__attribute((ns_consumed)) id, __attribute((ns_consumed)) id){};
 
 blk1 d4 = ^void (id, id) {}; // expected-error {{cannot initialize a variable of type '__strong blk1'}}
+
+
+typedef void (*releaser_t)(__attribute__((ns_consumed)) id);
+
+void normalFunction(id);
+releaser_t r1 = normalFunction; // expected-error {{cannot initialize a variable of type 'releaser_t'}}
+
+void releaser(__attribute__((ns_consumed)) id);
+releaser_t r2 = releaser; // no-warning
+
+template <typename T>
+void templateFunction(T) {} // expected-note {{candidate function}}
+releaser_t r3 = templateFunction<id>; // expected-error {{address of overloaded function 'templateFunction' does not match required type 'void (id)'}}
+
+template <typename T>
+void templateReleaser(__attribute__((ns_consumed)) T) {}
+releaser_t r4 = templateReleaser<id>; // no-warning
+
+
+@class AntiRelease, ExplicitAntiRelease, ProRelease;
+
+template<>
+void templateFunction(__attribute__((ns_consumed)) AntiRelease *); // expected-error {{no function template matches function template specialization 'templateFunction'}}
+
+template<>
+void templateReleaser(AntiRelease *); // expected-error {{no function template matches function template specialization 'templateReleaser'}}
+
+template<>
+void templateReleaser(ExplicitAntiRelease *) {} // expected-error {{no function template matches function template specialization 'templateReleaser'}}
+
+template<>
+void templateReleaser(__attribute__((ns_consumed)) ProRelease *); // no-warning