[Vulkan][Codegen] Read vulkan device capabilities/limits from Target

- Previously, the codegen assumed that all device features were
  present.  Now, the codegen reads device capabilities from the
  Target, and throws an error if codegen would require use of an
  unsupported feature.

src/target/spirv/spirv_support.cc

@@ -35,17 +35,45 @@ SPIRVSupport::SPIRVSupport(tvm::Target target) {
   ICHECK_EQ(target->kind->device_type, kDLVulkan)
       << "SPIRVSupport can only be checked for vulkan device type";
 
-  // Currently, this codifies the assumptions that were present and
-  // implicit in previous implementations.  In the future, this will
-  // pull information from the specified `Target`.
-
-  supports_storage_buffer_storage_class = (SPV_VERSION >= 0x10300);
-  supports_storage_buffer_8bit_access = true;
-  supports_storage_buffer_16bit_access = true;
-  supports_float16 = true;
-  supports_int8 = true;
-  supports_int16 = true;
-  supports_int64 = true;
+  if (target->GetAttr<Integer>("supported_subgroup_operations")) {
+    supported_subgroup_operations =
+        target->GetAttr<Integer>("supported_subgroup_operations").value();
+  }
+  if (target->GetAttr<Integer>("max_push_constants_size")) {
+    max_push_constants_size = target->GetAttr<Integer>("max_push_constants_size").value();
+  }
+  if (target->GetAttr<Integer>("max_uniform_buffer_range")) {
+    max_uniform_buffer_range = target->GetAttr<Integer>("max_uniform_buffer_range").value();
+  }
+  if (target->GetAttr<Integer>("max_storage_buffer_range")) {
+    max_storage_buffer_range = target->GetAttr<Integer>("max_storage_buffer_range").value();
+  }
+  if (target->GetAttr<Integer>("max_per_stage_descriptor_storage_buffer")) {
+    max_per_stage_descriptor_storage_buffers =
+        target->GetAttr<Integer>("max_per_stage_descriptor_storage_buffer").value();
+  }
+  if (target->GetAttr<Bool>("supports_storage_buffer_storage_class")) {
+    supports_storage_buffer_storage_class =
+        target->GetAttr<Bool>("supports_storage_buffer_storage_class").value();
+  }
+  if (target->GetAttr<Bool>("supports_8bit_buffer")) {
+    supports_storage_buffer_8bit_access = target->GetAttr<Bool>("supports_8bit_buffer").value();
+  }
+  if (target->GetAttr<Bool>("supports_16bit_buffer")) {
+    supports_storage_buffer_16bit_access = target->GetAttr<Bool>("supports_16bit_buffer").value();
+  }
+  if (target->GetAttr<Bool>("supports_float16")) {
+    supports_float16 = target->GetAttr<Bool>("supports_float16").value();
+  }
+  if (target->GetAttr<Bool>("supports_int8")) {
+    supports_int8 = target->GetAttr<Bool>("supports_int8").value();
+  }
+  if (target->GetAttr<Bool>("supports_int16")) {
+    supports_int16 = target->GetAttr<Bool>("supports_int16").value();
+  }
+  if (target->GetAttr<Bool>("supports_int64")) {
+    supports_int64 = target->GetAttr<Bool>("supports_int64").value();
+  }
 }
 
 }  // namespace codegen