Add support for building with thinLTO (#3484)
Add support for building with thinLTO (#3484)

Supports Clang, on win/mac/linux. Uses lld on Linux and Windows.

I haven't tested yet on Mac, but in theory it should work.
WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen,WebAssembly/binaryen