servo: Merge #9937 - Detect Cygwin environment on Windows (from sorpaas:fix/cygwin); r=Wafflespeanut

Currently if Servo is built using Cygwin, it is incorrectly classified as "unknown" host, which makes downloading Rust and Cargo fail. This pull request fixes that.

Source-Repo: https://github.com/servo/servo
Source-Revision: 31bdcbe7258cfa796b88505f5e29d75920e5c708

servo/python/servo/command_base.py

@@ -41,7 +41,7 @@ def host_triple():
         os_type = "apple-darwin"
     elif os_type == "android":
         os_type = "linux-androideabi"
-    elif os_type == "windows" or os_type.startswith("mingw64_nt-"):
+    elif os_type == "windows" or os_type.startswith("mingw64_nt-") or os_type.startswith("cygwin_nt-"):
         os_type = "pc-windows-gnu"
     else:
         os_type = "unknown"