Fix crash if a submodule @imports another submodule from the same module. The
test also adds FIXMEs for a number of places where imports and includes of
submodules don't work very well.

llvm-svn: 193005
diff --git a/clang/test/Modules/Inputs/submodules/import-self-d.h b/clang/test/Modules/Inputs/submodules/import-self-d.h
new file mode 100644
index 0000000..e32a6f5
--- /dev/null
+++ b/clang/test/Modules/Inputs/submodules/import-self-d.h
@@ -0,0 +1 @@
+typedef int MyTypeD;