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](https://github.com/rust-lang/rust/issues/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

4 files changed, 26 insertions, 3 deletions

diff --git a/src/ci/docker/host-x86_64/dist-various-1/Dockerfile b/src/ci/docker/host-x86_64/dist-various-1/Dockerfile
index 5c459e5cd18..4d5980027ca 100644
--- a/src/ci/docker/host-x86_64/dist-various-1/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-various-1/Dockerfile
@@ -55,6 +55,12 @@ RUN ./install-riscv64-none-elf.sh
 COPY host-x86_64/dist-various-1/install-riscv32-none-elf.sh /build
 RUN ./install-riscv32-none-elf.sh
 
+COPY host-x86_64/dist-various-1/install-emscripten.sh /build
+RUN ./install-emscripten.sh
+
+# Add Emscripten to PATH
+ENV PATH="/build/emsdk:/build/emsdk/upstream/emscripten:/build/emsdk/node/current/bin:${PATH}"
+
 # Suppress some warnings in the openwrt toolchains we downloaded
 ENV STAGING_DIR=/tmp
 
diff --git a/src/ci/docker/host-x86_64/dist-various-1/install-emscripten.sh b/src/ci/docker/host-x86_64/dist-various-1/install-emscripten.sh
new file mode 100755
index 00000000000..eeb54ca67f7
--- /dev/null
+++ b/src/ci/docker/host-x86_64/dist-various-1/install-emscripten.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -ex
+
+apt-get update
+apt-get install -y --no-install-recommends \
+  nodejs \
+  default-jre
+
+git clone https://github.com/emscripten-core/emsdk.git
+cd emsdk
+./emsdk install latest
+./emsdk activate latest
diff --git a/src/ci/docker/host-x86_64/dist-various-2/Dockerfile b/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
index 0855ea222a3..33d55123936 100644
--- a/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
@@ -59,6 +59,10 @@ ENV \
     CXX_i686_unknown_uefi=clang++-11 \
     CC_x86_64_unknown_uefi=clang-11 \
     CXX_x86_64_unknown_uefi=clang++-11 \
+    CC_wasm32_unknown_unknown=clang-11 \
+    CXX_wasm32_unknown_unknown=clang++-11 \
+    CC_wasm32v1_none=clang-11 \
+    CXX_wasm32v1_none=clang++-11 \
     CC=gcc-9 \
     CXX=g++-9
 
diff --git a/src/ci/docker/host-x86_64/test-various/Dockerfile b/src/ci/docker/host-x86_64/test-various/Dockerfile
index 82a820c859d..6ff529c9e71 100644
--- a/src/ci/docker/host-x86_64/test-various/Dockerfile
+++ b/src/ci/docker/host-x86_64/test-various/Dockerfile
@@ -4,6 +4,7 @@ ARG DEBIAN_FRONTEND=noninteractive
 RUN apt-get update && apt-get install -y --no-install-recommends \
   clang-11 \
   llvm-11 \
+  gcc-multilib \
   g++ \
   make \
   ninja-build \
@@ -59,8 +60,8 @@ RUN curl -L https://github.com/bytecodealliance/wasmtime/releases/download/v19.0
   tar -xJ
 ENV PATH "$PATH:/wasmtime-v19.0.0-x86_64-linux"
 
-ENV WASM_TARGETS=wasm32-wasip1
-ENV WASM_SCRIPT python3 /checkout/x.py --stage 2 test --host='' --target $WASM_TARGETS \
+ENV WASM_WASIP_TARGET=wasm32-wasip1 
+ENV WASM_WASIP_SCRIPT python3 /checkout/x.py --stage 2 test --host='' --target $WASM_WASIP_TARGET \
   tests/run-make \
   tests/ui \
   tests/mir-opt \
@@ -91,4 +92,4 @@ ENV UEFI_SCRIPT python3 /checkout/x.py --stage 2 build --host='' --target $UEFI_
   python3 /checkout/x.py --stage 2 test tests/run-make/uefi-qemu/rmake.rs --target i686-unknown-uefi && \
   python3 /checkout/x.py --stage 2 test tests/run-make/uefi-qemu/rmake.rs --target x86_64-unknown-uefi
 
-ENV SCRIPT $WASM_SCRIPT && $NVPTX_SCRIPT && $MUSL_SCRIPT && $UEFI_SCRIPT
+ENV SCRIPT $WASM_WASIP_SCRIPT && $NVPTX_SCRIPT && $MUSL_SCRIPT && $UEFI_SCRIPT