Use LuaJIT build script from Megasource's 12.x branch.

love/src/jni/LuaJIT-2.1/build_instructions.bat

@@ -1,9 +1,10 @@
-rem Build instruction assume using WSL + Clang for Windows (with MSVC x86+x64 toolset for -m32 switch)
-rem This assume NDK r23c or later. See https://github.com/LuaJIT/LuaJIT/issues/477 for more information.
+rem Build instruction assume using WSL.
 
-rem Make sure LuaJIT (yes, you need LuaJIT interpreter) and the NDK toolchain binaries is already in
-rem your PATH environment variable. If you're confused which part of the NDK should be added your path:
-rem <NDK_ROOT>\toolchains\llvm\prebuilt\windows-x86_64\bin
+rem Prerequisite:
+rem * Android NDK r23 or later.
+rem * GCC in WSL, with multilib.
+rem * NDK path appended to %PATH% in Windows. (Protip: path %PATH%;<NDK_ROOT>\toolchains\llvm\prebuilt\windows-x86_64\bin)
+rem * LuaJIT interpreter, either in Windows or WSL.
 
 mkdir android\arm64-v8a
 mkdir android\armeabi-v7a
@@ -13,16 +14,32 @@ mkdir android\x86_64
 rem Reset error level
 type nul
 
+rem Find LuaJIT
+luajit -v
+if "%ERRORLEVEL%" == "0" (
+	set LUAJIT_INTERPRETER=luajit.exe
+	goto :ljdetermined
+)
+wsl luajit -v
+if "%ERRORLEVEL%" == "0" (
+	set LUAJIT_INTERPRETER=luajit
+	goto :ljdetermined
+)
+echo You need LuaJIT either in Windows or in WSL!
+goto :error
+
+:ljdetermined
+
 rem ARMv8
 call :compile arm64-v8a aarch64-linux-android 21
 if "%ERRORLEVEL%" == "1" goto :error
 
 rem ARMv7
-call :compile armeabi-v7a armv7a-linux-androideabi 16 -m32
+call :compile armeabi-v7a armv7a-linux-androideabi 21 -m32
 if not "%ERRORLEVEL%" == "0" goto :error
 
 rem x86
-call :compile x86 i686-linux-android 16 -m32
+call :compile x86 i686-linux-android 21 -m32
 if not "%ERRORLEVEL%" == "0" goto :error
 
 rem x86_64
@@ -35,24 +52,38 @@ goto :done
 if exist android\%1\libluajit.a exit /b 0
 wsl make clean
 if not "%ERRORLEVEL%" == "0" goto :error
-wsl make HOST_LUA=luajit.exe "HOST_CC=clang.exe %4" HOST_CFLAGS=-D_CRT_SECURE_NO_WARNINGS CC=clang CROSS=%2- "STATIC_CC=%2%3-clang -fPIC" "DYNAMIC_CC=%2%3-clang -fPIC" "TARGET_AR=llvm-ar.exe rcus" TARGET_LD=%2%3-clang CCDEBUG=-g TARGET_LDFLAGS=-fuse-ld=lld TARGET_STRIP=llvm-strip.exe amalg -j%NUMBER_OF_PROCESSORS%
+wsl make ^
+	HOST_LUA=%LUAJIT_INTERPRETER% ^
+	"HOST_CC=gcc %4" ^
+	HOST_CFLAGS=-D_CRT_SECURE_NO_WARNINGS ^
+	CC=clang ^
+	CROSS=%2- ^
+	"STATIC_CC=%2%3-clang -fPIC" ^
+	"DYNAMIC_CC=%2%3-clang -fPIC" ^
+	"TARGET_AR=llvm-ar.exe rcus" ^
+	TARGET_SYS=Linux ^
+	TARGET_LD=%2%3-clang ^
+	TARGET_LDFLAGS=-fuse-ld=lld ^
+	TARGET_STRIP=llvm-strip.exe ^
+	TARGET_SONAME=libluajit.so ^
+	CCDEBUG=-g ^
+	"GIT_RELVER=cp ../.relver luajit_relver.txt" ^
+	amalg -j%NUMBER_OF_PROCESSORS%
 if not "%ERRORLEVEL%" == "0" goto :error
 copy src\libluajit.a android\%1\libluajit.a
 if not "%ERRORLEVEL%" == "0" goto :error
+copy src\libluajit.so android\%1\libluajit.so
+if not "%ERRORLEVEL%" == "0" goto :error
+copy src\luajit.h android\%1\luajit.h
+if not "%ERRORLEVEL%" == "0" goto :error
 xcopy src\jit android\%1\jit /I
+if not "%ERRORLEVEL%" == "0" goto :error
 del android\%1\jit\.gitignore
 goto :done
 
-:post_cleanup
-del src\host\buildvm.ilk
-del src\host\buildvm.pdb
-exit /b 0
-
 :error
-call :post_cleanup
 exit /b 1
 
 :done
 wsl make clean
-call :post_cleanup
 exit /b 0