Merge #1273

1273: Properly return native shader module errors to users r=kvark a=Gordon-F

**Testing**
Disable `cross` feature, break `naga` and see what happens 😄 

```log
wgpu error: Validation Error

Caused by:
    In Device::create_render_pipeline
    Internal error in stage VERTEX: Error compiling the shader "\"Compilation failed: \\n\\nprogram_source:1:1: error: unknown type name \\\'sadgasdgasdgasdg\\\'\\nsadgasdgasdgasdg aasdgadsgb>\\n^\\nprogram_source:1:28: error: expected \\\';\\\' after top level declarator\\nsadgasdgasdgasdg aasdgadsgb>\\n   
```



Co-authored-by: Gordon-F <ishaposhnik@icloud.com>

wgpu-core/src/conv.rs

@@ -154,6 +154,25 @@ pub fn map_shader_stage_flags(shader_stage_flags: wgt::ShaderStage) -> hal::pso:
     value
 }
 
+pub fn map_hal_flags_to_shader_stage(
+    shader_stage_flags: hal::pso::ShaderStageFlags,
+) -> wgt::ShaderStage {
+    use hal::pso::ShaderStageFlags as H;
+    use wgt::ShaderStage as Ss;
+
+    let mut value = Ss::empty();
+    if shader_stage_flags.contains(H::VERTEX) {
+        value |= Ss::VERTEX;
+    }
+    if shader_stage_flags.contains(H::FRAGMENT) {
+        value |= Ss::FRAGMENT;
+    }
+    if shader_stage_flags.contains(H::COMPUTE) {
+        value |= Ss::COMPUTE;
+    }
+    value
+}
+
 pub fn map_extent(extent: &wgt::Extent3d, dim: wgt::TextureDimension) -> hal::image::Extent {
     hal::image::Extent {
         width: extent.width,

wgpu-core/src/device/mod.rs

@@ -1940,10 +1940,15 @@ impl<B: GfxBackend> Device<B> {
         let raw =
             unsafe { self.raw.create_compute_pipeline(&pipeline_desc, None) }.map_err(|err| {
                 match err {
-                    hal::pso::CreationError::OutOfMemory(_) => DeviceError::OutOfMemory,
+                    hal::pso::CreationError::OutOfMemory(_) => {
+                        pipeline::CreateComputePipelineError::Device(DeviceError::OutOfMemory)
+                    }
+                    hal::pso::CreationError::ShaderCreationError(_, error) => {
+                        pipeline::CreateComputePipelineError::Internal(error)
+                    }
                     _ => {
                         log::error!("failed to create compute pipeline: {}", err);
-                        DeviceError::OutOfMemory
+                        pipeline::CreateComputePipelineError::Device(DeviceError::OutOfMemory)
                     }
                 }
             })?;
@@ -2391,10 +2396,18 @@ impl<B: GfxBackend> Device<B> {
         let raw =
             unsafe { self.raw.create_graphics_pipeline(&pipeline_desc, None) }.map_err(|err| {
                 match err {
-                    hal::pso::CreationError::OutOfMemory(_) => DeviceError::OutOfMemory,
+                    hal::pso::CreationError::OutOfMemory(_) => {
+                        pipeline::CreateRenderPipelineError::Device(DeviceError::OutOfMemory)
+                    }
+                    hal::pso::CreationError::ShaderCreationError(stage, error) => {
+                        pipeline::CreateRenderPipelineError::Internal {
+                            stage: conv::map_hal_flags_to_shader_stage(stage),
+                            error,
+                        }
+                    }
                     _ => {
                         log::error!("failed to create graphics pipeline: {}", err);
-                        DeviceError::OutOfMemory
+                        pipeline::CreateRenderPipelineError::Device(DeviceError::OutOfMemory)
                     }
                 }
             })?;

wgpu-core/src/pipeline.rs

@@ -113,6 +113,8 @@ pub enum CreateComputePipelineError {
     Implicit(#[from] ImplicitLayoutError),
     #[error(transparent)]
     Stage(validation::StageError),
+    #[error("Internal error: {0}")]
+    Internal(String),
 }
 
 #[derive(Debug)]
@@ -234,6 +236,11 @@ pub enum CreateRenderPipelineError {
         #[source]
         error: validation::StageError,
     },
+    #[error("Internal error in stage {stage:?}: {error}")]
+    Internal {
+        stage: wgt::ShaderStage,
+        error: String,
+    },
 }
 
 bitflags::bitflags! {