Hello!
I was receiving this warning while compiling for linux:
```
src/host/premake.c: In function ‘premake_init’:
src/host/premake.c:197:36: warning: multi-character character constant [-Wmultichar]
lua_rawseti(L, LUA_REGISTRYINDEX, 'SHIM');
^~~~~~
```
Instead of disabling the warning, I've decided to convert that array key to
an expression.
And I've tested with following compilers:
gcc version 7.3.0 (Ubuntu 7.3.0-27ubuntu1~18.04)
gcc version 6.3.0 20170516 (Debian 6.3.0-18+deb9u1)
Thank you
