Drop -Wduplicated-branches

This seems to produce a bunch of frustrating case notably on 32bit

Author: Girgias

Zend/Zend.m4

@@ -216,7 +216,6 @@ test -n "$GCC" && CFLAGS="-Wall -Wextra -Wno-strict-aliasing -Wno-implicit-fallt
 dnl Check if compiler supports -Wno-clobbered (only GCC)
 AX_CHECK_COMPILE_FLAG([-Wno-clobbered], CFLAGS="-Wno-clobbered $CFLAGS", , [-Werror])
 AX_CHECK_COMPILE_FLAG([-Wduplicated-cond], CFLAGS="-Wduplicated-cond $CFLAGS", , [-Werror])
-AX_CHECK_COMPILE_FLAG([-Wduplicated-branches], CFLAGS="-Wduplicated-branches $CFLAGS", , [-Werror])
 AX_CHECK_COMPILE_FLAG([-Wlogical-op], CFLAGS="-Wlogical-op $CFLAGS", , [-Werror])
 AX_CHECK_COMPILE_FLAG([-Wformat-truncation ], CFLAGS="-Wformat-truncation $CFLAGS", , [-Werror])