Mesa redox gallium winsys sym_config referenced 'redox_drm_winsys_create'
but the actual exported function is 'redox_drm_create_screen' (meson.build:11).
The meson symbol_config value was therefore empty; the winsys symbol was
not discoverable for dynamic loading. Fix the name match.
scheme.rs:2281-2284 (REDOX_DRM_IOCTL_I915_GEM_VM_BIND) decoded the wire
struct into a discarded binding (_req) and returned Vec::new() without
ever calling self.driver.i915_gem_vm_bind(). Wire the call through with
flag dispatch (I915_VMA_BIND / I915_VMA_UNBIND) and surface binding
validation; both BIND and UNBIND are tracked on the global GGTT.
scheme.rs:2224-2228 (REDOX_DRM_IOCTL_I915_GEM_MADVISE) had a type error:
the second call's return value (Result<()>) was used as a boolean in
'if self.driver.i915_gem_madvise(req.handle, 0)? { 1 } else { 0 }'.
Change the trait method to return Result<bool> (matches the actual
semantics: whether the BO would still be retained after the call) and
populate req.retained from the bool.
Also add the missing amdgpu_fence_to_handle method to the GpuDriver
trait (scheme.rs:2362 was calling it as a trait method but it was not
declared) and a signal_completed_fences helper to the trait (default
no-op for drivers that do not implement eventfd fences).
vasilito
4c4a731ed6