[infer][build] Treating OCaml compiler warnings as build-blocking errors

Summary: Keep the codebase high-quality by preventing the introduction of warnings.

infer/src/Makefile

@@ -43,7 +43,7 @@ ifneq ($(wildcard $(BUILDDIR)/sanitize.sh),)
 endif
 
 GLOBAL_LFLAGS =  -annot
-GLOBAL_CFLAGS = -bin-annot
+GLOBAL_CFLAGS = "-bin-annot -warn-error @5@8@10..12@20@26"
 GLOBAL_OPTIONS = -lflags $(GLOBAL_LFLAGS) -cflags $(GLOBAL_CFLAGS) $(addprefix -lib ,$(GLOBAL_LIBS))
 
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