Auto merge of #146148 - Flakebi:global-addrspace-test, r=Mark-Simulacrum

Add amdgpu test for addrspacecasting global vars and the gpu-kernel calling convention

Add two tests that can now be added, as the amdgpu is merged.

- Global variables are casted to the default address space since rust-lang/rust#135026
- gpu-kernel calling convention, translatos to amdgpu_kernel rust-lang/rust#135047

Tracking issue: rust-lang/rust#135024

Author: bors