Upgrade node from v16.20.0 to v18.20.3

Node v18 is that current LTS release of node and v18.20.3 is the latest
release of v18.

This change means that emsdk is no longer installable on Ubuntu/Bionic
18.04, and we now require Ubuntu/Focal 20.04.

See: #1183
Fixes: #1173

.circleci/config.yml

@@ -4,9 +4,9 @@ orbs:
   win: circleci/[email protected]
 
 executors:
-  bionic:
+  focal:
     docker:
-      - image: buildpack-deps:bionic
+      - image: buildpack-deps:focal
   mac:
     environment:
       EMSDK_NOTTY: "1"
@@ -50,7 +50,7 @@ commands:
 
 jobs:
   flake8:
-    executor: bionic
+    executor: focal
     steps:
       - checkout
       - run:
@@ -65,14 +65,9 @@ jobs:
       - run: python2 -m flake8 --show-source --statistics --extend-exclude=./scripts
       - run: python3 -m flake8 --show-source --statistics
   test-linux:
-    executor: bionic
+    executor: focal
     environment:
       EMSDK_NOTTY: "1"
-      # This is needed because the old gcc-7 that is installed on debian/bionic
-      # generates warnings about unused variables when doing C++17
-      # destructuring:
-      # https://github.com/WebAssembly/binaryen/issues/4353
-      CXXFLAGS: "-Wno-unused-variable"
       # I don't know why circleci VMs pretent to have 36 cores but its a lie.
       EMSDK_NUM_CORES: "4"
     steps:
@@ -174,7 +169,7 @@ jobs:
             test/test_path_preservation.ps1
 
   build-docker-image-x64:
-    executor: bionic
+    executor: focal
     steps:
       - checkout
       - run:
@@ -190,7 +185,7 @@ jobs:
           command: make -C ./docker version=latest test
 
   publish-docker-image-x64:
-    executor: bionic
+    executor: focal
     steps:
       - checkout
       - run:
@@ -226,7 +221,7 @@ jobs:
             make -C ./docker version=${CIRCLE_TAG} alias=${CIRCLE_TAG}-arm64 only_alias=true push
 
   test-bazel-linux:
-    executor: bionic
+    executor: focal
     steps:
       - checkout
       - run: apt-get install -q -y curl gnupg

emsdk_manifest.json

@@ -346,6 +346,54 @@
     "activated_env": "EMSDK_NODE=%installation_dir%/bin/node%.exe%"
   },
 
+  {
+    "id": "node",
+    "version": "18.20.3",
+    "bitness": 32,
+    "arch": "x86",
+    "windows_url": "node-v18.20.3-win-x86.zip",
+    "activated_path": "%installation_dir%/bin",
+    "activated_path_skip": "node",
+    "activated_cfg": "NODE_JS='%installation_dir%/bin/node%.exe%'",
+    "activated_env": "EMSDK_NODE=%installation_dir%/bin/node%.exe%"
+  },
+  {
+    "id": "node",
+    "version": "18.20.3",
+    "arch": "arm",
+    "bitness": 32,
+    "linux_url": "node-v18.20.3-linux-armv7l.tar.xz",
+    "activated_path": "%installation_dir%/bin",
+    "activated_path_skip": "node",
+    "activated_cfg": "NODE_JS='%installation_dir%/bin/node%.exe%'",
+    "activated_env": "EMSDK_NODE=%installation_dir%/bin/node%.exe%"
+  },
+  {
+    "id": "node",
+    "version": "18.20.3",
+    "bitness": 64,
+    "arch": "x86_64",
+    "macos_url": "node-v18.20.3-darwin-x64.tar.gz",
+    "windows_url": "node-v18.20.3-win-x64.zip",
+    "linux_url": "node-v18.20.3-linux-x64.tar.xz",
+    "activated_path": "%installation_dir%/bin",
+    "activated_path_skip": "node",
+    "activated_cfg": "NODE_JS='%installation_dir%/bin/node%.exe%'",
+    "activated_env": "EMSDK_NODE=%installation_dir%/bin/node%.exe%"
+  },
+  {
+    "id": "node",
+    "version": "18.20.3",
+    "arch": "arm64",
+    "bitness": 64,
+    "macos_url": "node-v18.20.3-darwin-arm64.tar.gz",
+    "linux_url": "node-v18.20.3-linux-arm64.tar.xz",
+    "activated_path": "%installation_dir%/bin",
+    "activated_path_skip": "node",
+    "activated_cfg": "NODE_JS='%installation_dir%/bin/node%.exe%'",
+    "activated_env": "EMSDK_NODE=%installation_dir%/bin/node%.exe%"
+  },
+
 
   {
     "id": "python",

scripts/update_node.py

@@ -16,8 +16,8 @@
 import os
 import shutil
 
-version = '16.20.0'
-base = 'https://nodejs.org/dist/latest-v16.x/'
+version = '18.20.3'
+base = 'https://nodejs.org/dist/latest-v18.x/'
 upload_base = 'gs://webassembly/emscripten-releases-builds/deps/'
 
 suffixes = [