Enable all warnings and pedantic mode

This can be an issue for portable code, but we build for single platform
and single compiler, so we should be ok.

Don't treat warnings as errors to reduced the chance that the build will
fail on older macOS versions or future versions.

Signed-off-by: Nir Soffer <[email protected]>

Author: nirs

Makefile

@@ -13,7 +13,7 @@ GZIP ?= gzip -9 -n
 DIFFOSCOPE ?= diffoscope
 STRIP ?= strip
 
-CFLAGS ?= -O3
+CFLAGS ?= -O3 -Wall -Wextra -pedantic
 ifeq ($(DEBUG),1)
 	CFLAGS += -g
 endif