Build Fuchsia tests in CI

This would have caught
rust-lang/rust-clippy#11952.

Author: tmandry

src/ci/docker/host-x86_64/x86_64-gnu-integration/Dockerfile

@@ -44,6 +44,7 @@ ENV CARGO_TARGET_X86_64_FUCHSIA_RUSTFLAGS \
 
 ENV TARGETS=x86_64-fuchsia
 ENV TARGETS=$TARGETS,x86_64-unknown-linux-gnu
+ENV TARGETS=$TARGETS,wasm32-unknown-unknown
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh

src/ci/docker/host-x86_64/x86_64-gnu-integration/build-fuchsia.sh

@@ -6,7 +6,9 @@
 set -euf -o pipefail
 
 INTEGRATION_SHA=66793c4894bf6204579bbee3b79956335f31c768
-PICK_REFS=()
+PICK_REFS=(
+    refs/changes/86/965586/2
+)
 
 checkout=fuchsia
 jiri=.jiri_root/bin/jiri