CI: Temporarily override country MAKE for TC2

Unfortunately the make supplied with Turbo C 2.01 doesn't like variables
being passed in on the command line, so use GNU make instead.
Note:
  As 'country' is a submodule it can't do `!include "../mkfiles/generic.mak"`
as that would be outside its repository and would break the standalone build,
hence the reason its DIRSEP and CP vars are set on the outside. As its
'production' target is used by the main makefile, there's no opportunity to
hardcode those values to DOS specific ones there either.

Author: andrewbird

build.bat

@@ -131,7 +131,9 @@ echo.
 echo Process COUNTRY +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 echo.
 cd ..\country
-%MAKE% DIRSEP=\ CP=copy production
+set TMAKE=%MAKE%
+if "%COMPILER%" == "TC2" set TMAKE=c:\bin\make
+%TMAKE% DIRSEP=\ CP=copy production
 if errorlevel 1 goto abort-cd
 
 echo.