Incorporate _tags file into Makefile

Summary:
Handle building in debug mode by passing command line options set in
the Makefile, as all the other configuration of ocamlbuild is done
through command line options.

Reviewed By: jvillard

Differential Revision: D3202085

fb-gh-sync-id: d467019
fbshipit-source-id: d467019

infer/src/Makefile.in

@@ -33,6 +33,8 @@ OCAML_FATAL_WARNINGS = +5+6+8+10+11+12+18+19+20+26+29+27+32+33+34+35+37+38+39
 
 OCAMLBUILD_OPTIONS = \
                      -classic-display \
+                     -r \
+                     -cflags -g -lflags -g \
                      -cflags -short-paths \
                      -cflags -safe-string \
                      -cflags -principal \

infer/src/_tags

@@ -1 +0,0 @@
-true: debug