Add the equivalent of -Werror for wasm-ld

Author: adamscott

platform/web/detect.py

@@ -130,6 +130,10 @@ def configure(env: "SConsEnvironment"):
     ## Copy env variables.
     env["ENV"] = os.environ
 
+    # This makes `wasm-ld` treat all warnings as errors.
+    if env["werror"]:
+        env.Append(LINKFLAGS=["-Wl,--fatal-warnings"])
+
     # LTO
 
     if env["lto"] == "auto":  # Enable LTO for production.