Add support for C++ default arguments, and rework Parse-Sema 
interaction for function parameters, fixing PR2046.

Patch by Doug Gregor!

llvm-svn: 49369
diff --git a/clang/test/Sema/default2.cpp b/clang/test/Sema/default2.cpp
new file mode 100644
index 0000000..0fe04ab
--- /dev/null
+++ b/clang/test/Sema/default2.cpp
@@ -0,0 +1,12 @@
+// RUN: clang -fsyntax-only -verify %s
+void f(int i, int j, int k = 3);
+void f(int i, int j = 2, int k);
+void f(int i = 1, int j, int k);
+
+void i()
+{
+  f();
+  f(0);
+  f(0, 1);
+  f(0, 1, 2);
+}