Fix half of emscripten's failing tests

[tomaka]

Before this PR:

test result: FAILED. 2039 passed; 327 failed; 2 ignored; 0 measured

After:

test result: FAILED. 2232 passed; 134 failed; 2 ignored; 0 measured

r? @brson

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @brson (or someone else) soon.

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[oli-obk]

why isn't the force_host statement also true for emscripten?

[tomaka]

The comment says if the library is built with force_host then it's ok to be a dylib as the host should always support dylibs, but emscripten doesn't support dynamic libraries at all (the "libraries" are just hidden javascript files).

[oli-obk]

yes, but the host can never be emscripten, right? That would mean we'd have a rustc that runs on emscripten.

I think force_host is just for rustc's unit tests when compiling a compiler plugin.

[tomaka]

That would mean we'd have a rustc that runs on emscripten.

Well, why not? 🐷

[brson]

@bors r+ Thanks @tomaka!

[bors]

📌 Commit 657f1cf has been approved by brson

[bors]

⌛️ Testing commit 657f1cf with merge aa1dc09...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-debug-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-linux-cross-opt, auto-linux-musl-64-opt, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-mac-ios-opt, auto-win-gnu-32-nopt-t, auto-win-gnu-32-opt, auto-win-gnu-64-nopt-t, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-opt