Rollup merge of #137457 - JayAndJef:issue-132802-fix, r=Kobzol

Fix host code appearing in Wasm binaries

This is a direct fix for issue [132802](rust-lang/rust#132802).
Followed the outline as follows:
> * give a hard error in bootstrap when using gcc to compile for wasm
> * change our CI to use clang instead of gcc
> * add a test that compiling a sample program for wasm32-unknown doesn't give any linker warnings

The `test-various` ci job was also changed.

try-job: test-various
try-job: dist-various-1
try-job: dist-various-2
try-job: x86_64-msvc-1

Author: jhpratt