Fix debug option for msvcbuild.bat.

src/msvcbuild.bat

@@ -53,8 +53,8 @@ buildvm -m folddef -o lj_folddef.h lj_opt_fold.c
 
 @if "%1" neq "debug" goto :NODEBUG
 @shift
-@set LJCOMPILE=%LJCOMPILE% /Zi /Fdluajit.pdb
-@set LJLINK=%LJLINK% /debug /PDB:luajit.pdb
+@set LJCOMPILE=%LJCOMPILE% /Zi
+@set LJLINK=%LJLINK% /debug
 :NODEBUG
 @if "%1"=="amalg" goto :AMALGDLL
 @if "%1"=="static" goto :STATIC