Teach the scan-build script to output to a chosen directory

scripts/test/scan-build.sh

@@ -46,6 +46,12 @@ NOISY_CHECKERS="\
     -enable-checker alpha.deadcode.UnreachableCode \
 "
 
+if test "x$SCAN_BUILD_OUTPUT" != "x"; then
+   OUTPUTARG="-o $SCAN_BUILD_OUTPUT"
+else
+   OUTPUTARG=""
+fi
+
 scan-build \
     $CHECKERS \
     ./configure
@@ -53,7 +59,7 @@ scan-build \
 make clean
 
 scan-build \
-    $CHECKERS \
+    $CHECKERS $OUTPUTARG \
     make -j5 -k
 
 CHECKERS="\