[SIL] Print full nested enum type name

ASTPrinter should print an extended type for enums,
(same as structs and classes) along with enum parents.

Author: polac24

lib/AST/ASTPrinter.cpp

@@ -1772,6 +1772,12 @@ static void printExtendedTypeName(Type ExtendedType, ASTPrinter &Printer,
       Printer << ".";
     }
   }
+  if (auto et = ExtendedType->getAs<EnumType>()) {
+    if (auto ParentType = et->getParent()) {
+      ParentType.print(Printer, Options);
+      Printer << ".";
+    }
+  }
 
   // Respect alias type.
   if (isa<NameAliasType>(ExtendedType.getPointer())) {

test/SIL/printer_include_decls.swift

@@ -36,9 +36,18 @@ class Foo {
 
   func m() {}
 // CHECK: func m()
+
+  enum E {}
+// CHECK: enum E
 }
 
 func bar(x: Foo) -> Int {
   return x.x
 }
 // CHECK: func bar(x: Foo) -> Int
+
+extension Foo.E {
+// CHECK: extension Foo.E {
+  func e(x: Foo.E) {}
+// CHECK: func e(x: Foo.E)
+}