strict mode incompatibility

[tsafin]

Most of a time I run Tarantool (LuaJIT flavour) in strict mode as it's enabled by default in Debug mode. This makes lldebugger.lua to generate very vague error messages, like:

LuajitError: .../debug/local-lua-debugger-vscode/debugger/lldebugger.lua:1922: variable 'lldebugger' is not declared
fatal error, exiting the event loop

That's due to access to undefined global at

_G.lldebugger = _G.lldebugger || ____exports;

Such access to _G should probably be wrapped in rawget/rawset to workaround strict mode messages here.