Include clang-check as part of the clang installation.

This also tidies up a couple of other tools we were (partially) installing:
* c-index-test was being installed but shouldn't be (it's just a clang-dev tool)
* diagtool was being installed in cmake but not make (& shouldn't be installed in either)

Review by Manuel Klimek, Doug Gregor, and Chandler Carruth.

llvm-svn: 161073
diff --git a/clang/tools/c-index-test/Makefile b/clang/tools/c-index-test/Makefile
index 284844f..932dbb2 100644
--- a/clang/tools/c-index-test/Makefile
+++ b/clang/tools/c-index-test/Makefile
@@ -17,6 +17,9 @@
 # No plugins, optimize startup time.
 TOOL_NO_EXPORTS = 1
 
+# Don't install this. It is used for tests.
+NO_INSTALL = 1
+
 LINK_COMPONENTS := support mc
 USEDLIBS = clang.a clangFrontend.a clangDriver.a \
 	   clangTooling.a \