[WIP] Fix environment constructing in MSYS2 shell#1191

Blackhex wants to merge 1 commit intoemscripten-core:mainemscripten-core/emsdk:mainfrom

Windows-on-ARM-Experiments:fix-msys2-construct-envWindows-on-ARM-Experiments/emsdk:fix-msys2-construct-envCopy head branch name to clipboard