Default OPTIMIZE_OPTION to -O2 on FreeBSD, at the request of the Clang/FreeBSD
folks. LLVM/Clang is miscompiled by the standard GCC at -O3.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102719 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 49a140c..3b40196 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -728,6 +728,7 @@
 case "$withval" in
   default)
     case "$llvm_cv_os_type" in
+    FreeBSD) optimize_option=-O2 ;;
     MingW) optimize_option=-O2 ;;
     *)     optimize_option=-O3 ;;
     esac ;;