Clang do so have plugins, we can't prune exports. Fixes plugin support.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@108054 91177308-0d34-0410-b5e6-96231b3b80d8

tools/driver/Makefile

@@ -17,9 +17,6 @@ else
   endif
 endif
 
-# Clang tool has no plugins, optimize startup time.
-TOOL_NO_EXPORTS = 1
-
 # Include this here so we can get the configuration of the targets that have
 # been configured for construction. We have to do this early so we can set up
 # LINK_COMPONENTS before including Makefile.rules