Modify mingw makefile to allow caller to specify LUA build parameters.

azure-pipelines.yml

@@ -110,6 +110,10 @@ steps:
   displayName: 'Windows MSBuild'
 
 - bash: |
+    export ADD_LUA=Y
+    export WANT_LUAC=N
+    export LUATOP=../submodules/lua
+    export LUASRC=../submodules/lua
     export ADD_CURSES=Y
     export PDCURSES_TOP=../submodules/pdcurses
     export LUA_VERSION=5.4.2

sys/winnt/Makefile.gcc

@@ -142,8 +142,11 @@ endif
 #    you'll need to specify the correct spot below in order to
 #    successfully build NetHack-3.7.
 #
+ifndef ADD_LUA
 ADD_LUA=Y
 LUATOP=../lib/lua-$(LUAVER)
+WANT_LUAC=Y
+endif
 #
 #==============================================================================
 # This marks the end of the BUILD DECISIONS section.
@@ -422,12 +425,18 @@ OPTIONS_FILE = $(DAT)\options
 ifndef LUAVER
 LUAVER   = 5.4.2
 endif
+ifndef LUASRC
 LUASRC   = $(LUATOP)/src
+endif
 LUALIB   = $(O)lua-$(LUAVER).static.a
 LUADLL   = $(O)lua-$(LUAVER).a
 LUAINCL  = -I$(LUASRC)
 #LUAFLAGS = unix added -lm here?
+ifeq "$(WANT_LUAC)" "Y"
 LUATARGETS = lua.exe luac.exe $(LUADLL) $(LUALIB)
+else
+LUATARGETS = lua.exe $(LUADLL) $(LUALIB)
+endif
 
 LUASRCFILES =   lapi.c lauxlib.c lbaselib.c lcode.c    \
 		lcorolib.c lctype.c ldblib.c ldebug.c ldo.c      \