Make binaryen optional and don't install it in CI

Author: fitzgen

.travis.yml

@@ -4,15 +4,6 @@ cache: cargo
 rust:
   - nightly
 
-# For `binaryen`.
-addons:
-  apt:
-    sources:
-      - 'ubuntu-toolchain-r-test'
-    packages:
-      - 'cmake'
-      - 'g++-5'
-
 env:
   matrix:
     - SCRIPT="./check.sh"
@@ -23,9 +14,6 @@ before_script:
   - rustup target add wasm32-unknown-unknown
   - which wasm-gc || cargo install --git https://github.com/alexcrichton/wasm-gc
   - which cargo-readme || cargo install cargo-readme
-  - test -d binaryen || git clone https://github.com/WebAssembly/binaryen.git
-  - export PATH="$PATH:$(pwd)/binaryen/bin"
-  - which wasm-opt || (cd binaryen && git pull origin master && cmake . && make -j4 && cd -)
 
 script:
   - "$SCRIPT"

build.sh

@@ -22,17 +22,23 @@ cargo build --release                         --target wasm32-unknown-unknown
 
 wasm-gc ../target/wasm32-unknown-unknown/release/wee_alloc_example.wasm \
         ../target/wasm32-unknown-unknown/release/wee_alloc_example.gc.wasm
-wasm-opt -Oz \
-         ../target/wasm32-unknown-unknown/release/wee_alloc_example.gc.wasm \
-         -o ../target/wasm32-unknown-unknown/release/wee_alloc_example.gc.opt.wasm
+
+if which wasm-opt; then
+    wasm-opt -Oz \
+             ../target/wasm32-unknown-unknown/release/wee_alloc_example.gc.wasm \
+             -o ../target/wasm32-unknown-unknown/release/wee_alloc_example.gc.opt.wasm
+fi
 
 cargo build --release --features size_classes --target wasm32-unknown-unknown
 
 wasm-gc ../target/wasm32-unknown-unknown/release/wee_alloc_example.wasm \
         ../target/wasm32-unknown-unknown/release/wee_alloc_example.size_classes.gc.wasm
-wasm-opt -Oz \
-         ../target/wasm32-unknown-unknown/release/wee_alloc_example.size_classes.gc.wasm \
-         -o ../target/wasm32-unknown-unknown/release/wee_alloc_example.size_classes.gc.opt.wasm
+
+if which wasm-opt; then
+    wasm-opt -Oz \
+             ../target/wasm32-unknown-unknown/release/wee_alloc_example.size_classes.gc.wasm \
+             -o ../target/wasm32-unknown-unknown/release/wee_alloc_example.size_classes.gc.opt.wasm
+fi
 
 wc -c ../target/wasm32-unknown-unknown/release/*.gc.opt.wasm