adding fallback to clang if gcc not available

configure

@@ -861,16 +861,6 @@ then
     CFG_DISABLE_JEMALLOC=1
 fi
 
-if [ $CFG_OSTYPE = unknown-freebsd ]
-then
-  CFG_FREEBSD_GCC_VERSION=$("CFG_GCC" --version 2>&1)
-  if [ $? -ne 0 ]
-  then
-    step_msg "GCC not installed on FreeBSD, forcing clang"
-    CFG_ENABLE_CLANG=1
-  fi
-fi
-
 # OS X 10.9, gcc is actually clang. This can cause some confusion in the build
 # system, so if we find that gcc is clang, we should just use clang directly.
 if [ $CFG_OSTYPE = apple-darwin -a -z "$CFG_ENABLE_CLANG" ]
@@ -909,6 +899,18 @@ then
     fi
 fi
 
+# If the clang isn't already enabled, check for GCC, and if it is missing, turn
+# on clang as a backup.
+if [ -z "$CFG_ENABLE_CLANG" ]
+then
+  CFG_GCC_VERSION=$("CFG_GCC" --version 2>&1)
+  if [ $? -ne 0 ]
+  then
+    step_msg "GCC not installed, will try using Clang"
+    CFG_ENABLE_CLANG=1
+  fi
+fi
+
 # Okay, at this point, we have made up our minds about whether we are
 # going to force CFG_ENABLE_CLANG or not; save the setting if so.
 if [ ! -z "$CFG_ENABLE_CLANG" ]