Get SHLIBEXT variable from configure script.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10933 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Makefile.config.in b/Makefile.config.in
index 5c614bc..84f3c1f 100644
--- a/Makefile.config.in
+++ b/Makefile.config.in
@@ -115,6 +115,9 @@
 # Disable LLC diffs for testing.
 @DISABLE_LLC_DIFFS@
 
+# Shared library extension for this platform.
+SHLIBEXT = @SHLIBEXT@
+
 ###########################################################################
 # Directory Configuration
 #	This section of the Makefile determines what is where.  To be