LICENSE

[vivanishin]

See if we have any licensing issues

• src/llvm/pass-rewrite-safepoints.cc is taken from LLVM sources
• src/llvm/llvm-stackmaps.cc is from JavaScriptCore

(but AFAIK everything should be OK provided we choose an appropriate license for LLV8).

Update licensing information in source files and elsewhere if there's a necessity.