Download ubuntu-18.04 WASI SDK distribution for Linux builds

Author: MaxDesiatov

utils/webassembly/linux/install-dependencies.sh

@@ -53,7 +53,7 @@ fi
 
 cmake --version
 
-$SWIFT_PATH/utils/webassembly/install-wasi-sdk.sh linux ubuntu
+$SWIFT_PATH/utils/webassembly/install-wasi-sdk.sh linux ubuntu-18.04
 
 # Link wasm32-wasi-unknown to wasm32-wasi because clang finds crt1.o from sysroot
 # with os and environment name `getMultiarchTriple`.
@@ -66,4 +66,4 @@ if [ -z $(which sccache) ]; then
   wget -O - "https://github.com/mozilla/sccache/releases/download/0.2.13/sccache-0.2.13-x86_64-unknown-linux-musl.tar.gz" | \
     sudo tar xz --strip-components 1
   sudo ln -sf /opt/sccache/sccache /usr/local/bin
-fi
+fi