Add some more gcc specific flags that are used somewhere in the tree (e.g. external/chromium_org) to CLANG_CONFIG_UNKNOWN_CFLAGS Change-Id: Icc572fdb6ea4ba818c4d18e430296589eb61bf55 Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>