SOCKS5 authentication broke Windows build

[riastradh-brave]

@darkdh reports that merging #470 caused the attached output in the Windows build of muon.

Presumably v8_context_generator depends on //net somewhere, and the BUILD.gn for //net in src/net doesn't have the new host_port_pair_auth.cc &c. files which live under src/electron/chromium_src and which I added in src/electron/chromium_src/BUILD.gn. Exactly which gn file should be updated to fix this is not immediately clear to me.

windows-fail.txt