Improve handling of base initializers. We now parse initializers in out of line decls, such as:

class C {
    C() { }
    
    int a;
};

C::C() : a(10) { }

We also diagnose when initializers are used on declarations that aren't constructors:

t.cpp:1:10: error: only constructors take base initializers
void f() : a(10) { }
         ^

Doug and/or Sebastian: I'd appreciate a review, especially the nested-name-spec test results (from the looks of it we now match gcc in that test.)

llvm-svn: 67672
diff --git a/clang/test/SemaCXX/nested-name-spec.cpp b/clang/test/SemaCXX/nested-name-spec.cpp
index 7aaa991..f575fb8 100644
--- a/clang/test/SemaCXX/nested-name-spec.cpp
+++ b/clang/test/SemaCXX/nested-name-spec.cpp
@@ -168,5 +168,6 @@
          // FIXME: ugly: expected-error{{invalid token after top level declarator}}
 
 X::X() : a(5) { } // expected-error{{use of undeclared identifier 'X'}} \
-      // expected-error{{expected function body after function declarator}}
+      // expected-error{{C++ requires a type specifier for all declarations}} \
+      // expected-error{{only constructors take base initializers}}