Add file_regex to CPP build system

Author: mr-sohel

CPP.sublime-build

@@ -5,5 +5,6 @@
         "-c",
         "g++ -std=gnu++17 -O2 -DLOCAL -Wall '${file}' -o '${file_path}/${file_base_name}' && timeout 3s '${file_path}/${file_base_name}'<in.txt>out.txt"
     ],
+    "file_regex": "^(..[^:]*):([0-9]+):?([0-9]+)?:? (.*)$",
     "selector": "source.c, source.c++"
-}
+}