PrimitiveTopology::PointList does not render on WebGL

[Oberdiah]

Description
Any draw commands using PrimitiveTopology::Pointlist do not render anything when using the WebGL backend. All other backends I've tested render as expected.

Repro steps
hello-triangle/shader.wgsl (So you can see the triangle points)

@vertex
fn vs_main(@builtin(vertex_index) in_vertex_index: u32) -> @builtin(position) vec4<f32> {
    let x = f32(i32(in_vertex_index) - 1);
    let y = f32(i32(in_vertex_index & 1u) * 2 - 1);
-   return vec4<f32>(x, y, 0.0, 1.0);
+   return vec4<f32>(x * 0.9, y * 0.9, 0.0, 1.0);
}

hello-triangle/main.rs

             entry_point: "fs_main",
             targets: &[Some(swapchain_format.into())],
         }),
-        primitive: wgpu::PrimitiveState::default(),
+        primitive: wgpu::PrimitiveState {
+            topology: wgpu::PrimitiveTopology::PointList,
+            ..wgpu::PrimitiveState::default()
+        },
         depth_stencil: None,
         multisample: wgpu::MultisampleState::default(),
         multiview: None,

Then running cargo run-wasm --example hello-triangle --features webgl

Expected vs observed behavior
Expected behaviour:
Three pixel-sized red dots on screen.
This can also be seen working by running the above code with cargo run --example hello-triangle
Observed behaviour:
No dots are rendered

Platform
Windows 10, wgpu 0.14.0, tested on both Firefox and Chrome.