Revert "disallow shadowing of globals by other globals in the same module, and disallow shadowing of locals"
Revert "disallow shadowing of globals by other globals in the same module, and disallow shadowing of locals"

This reverts commit aea98f0bb0b17cfcd4908fcefb2e060ac82a0ff8.

No idea why it worked so well for limited tests. I'll have a proper look at the situation later, meanwhile, the code is just dead weight.

bpr/SDC,DmitryOlshansky/SDC,deadalnix/SDC,SDC-Developers/SDC,sidmutha/SDC,bpr/SDC,UplinkCoder/SDC,DmitryOlshansky/SDC,UplinkCoder/SDC,schancel/SDC,SDC-Developers/SDC,UplinkCoder/SDC,sidmutha/SDC,SDC-Developers/SDC,bpr/SDC,JohanEngelen/SDC,JohanEngelen/SDC,DmitryOlshansky/SDC,deadalnix/SDC,carlor/SDC,JohanEngelen/SDC,deadalnix/SDC,schancel/SDC,sidmutha/SDC,schancel/SDC