feature = emscripten, compability fixes for wgpu-native

wgpu-core/Cargo.toml

@@ -20,6 +20,7 @@ trace = ["ron", "serde", "wgt/trace", "arrayvec/serde", "naga/serialize"]
 replay = ["serde", "wgt/replay", "arrayvec/serde", "naga/deserialize"]
 # Enable serializable compute/render passes, and bundle encoders.
 serial-pass = ["serde", "wgt/serde", "arrayvec/serde"]
+emscripten = ["hal/emscripten"]
 
 [dependencies]
 arrayvec = "0.7"

wgpu-hal/src/gles/egl.rs

@@ -501,6 +501,10 @@ impl Inner {
 
         // Testing if context can be binded without surface
         // and creating dummy pbuffer surface if not.
+        #[cfg(feature = "emscripten")]
+        let pbuffer = None;
+
+        #[cfg(not(feature = "emscripten"))]
         let pbuffer =
             if version >= (1, 5) || display_extensions.contains("EGL_KHR_surfaceless_context") {
                 log::info!("\tEGL context: +surfaceless");

wgpu/Cargo.toml

@@ -83,7 +83,7 @@ trace = ["serde", "wgc/trace"]
 replay = ["serde", "wgc/replay"]
 angle = ["wgc/angle"]
 webgl = ["wgc"]
-emscripten = ["webgl"]
+emscripten = ["webgl", "wgc/emscripten"]
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies.wgc]
 package = "wgpu-core"