Move include installation steps to better location, inside each include dir instead of at the top-level.

Also, don't set NO_INSTALL=1 for c-index-test.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@102724 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/Makefile b/include/Makefile
index 47daabc..f686d6a 100644
--- a/include/Makefile
+++ b/include/Makefile
@@ -1,4 +1,4 @@
 LEVEL = ../../..
-DIRS := clang
+DIRS := clang clang-c
 
 include $(LEVEL)/Makefile.common