Add MI355 to GPU mapping

Author: Ahajha

mojo/extensions.bzl

@@ -193,6 +193,7 @@ _gpu_toolchains_tag = tag_class(
                 "l4": "nvidia:89",
                 "mi300x": "amdgpu:gfx942",
                 "mi325": "amdgpu:gfx942",
+                "mi355": "amdgpu:gfx950",
                 "rtx5090": "nvidia:120a",
                 "metal3": "metal:30",
                 "metal4": "metal:40",
@@ -217,6 +218,7 @@ _gpu_toolchains_tag = tag_class(
                 "NVIDIA GeForce RTX 3090": "",
                 "MI300X": "mi300x",
                 "MI325": "mi325",
+                "MI355": "mi355",
                 "Navi": "radeon",
                 "AMD Radeon Graphics": "radeon",
                 "Metal 3": "metal3",