Add back the top-level target for 'llvm-config' and the dependency edge

to force it to build after all library targets so it has complete
dependency information. This should fix broken 'make install' with
CMake.

This is a partial revert of r143540, but it doesn't revert the most
important part of that change: removing the dependency edge from LLVM
tools to the llvm-config script.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143548 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-config/CMakeLists.txt

@@ -125,6 +125,13 @@ add_custom_command(OUTPUT ${LLVM_CONFIG}
   COMMENT "Building llvm-config script."
   )
 
+add_custom_target(llvm-config.target ALL
+  DEPENDS ${LLVM_CONFIG})
+
+# Ensure we build llvm-config after we build all of the libraries so that we
+# have their full dependencies.
+add_dependencies(llvm-config.target ${llvm_libs})
+
 install(FILES ${LLVM_CONFIG}
   PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE
   WORLD_READ WORLD_EXECUTE