configure: Don't warn about compiler-rt checked out into projects/.

llvm-svn: 146084
diff --git a/llvm/autoconf/configure.ac b/llvm/autoconf/configure.ac
index 3c3f412..22f41d1 100644
--- a/llvm/autoconf/configure.ac
+++ b/llvm/autoconf/configure.ac
@@ -114,6 +114,7 @@
       llvm-tv)      AC_CONFIG_SUBDIRS([projects/llvm-tv])   ;;
       safecode)     AC_CONFIG_SUBDIRS([projects/safecode]) ;;
       llvm-kernel)  AC_CONFIG_SUBDIRS([projects/llvm-kernel]) ;;
+      compiler-rt)       ;;
       llvm-gcc)       ;;
       test-suite)     ;;
       llvm-test)      ;;