Port to windows(GNU)

mingw build error

crystal build --cross-compile -Dgc_none --target x86_64-windows-gnu x.cr
LLVM ERROR: symbol '__ImageBase' can not be undefined in a subtraction expression

this error is very strange.

Is your goal to build with mingw?

yes

This issue may be interesting to you: https://github.com/crystal-lang/crystal/issues/6170