tests: Adopt ABI transmute tests from crashtests

Author: workingjubilee

tests/crashes/138738.rs

@@ -0,0 +1,7 @@
+#![feature(abi_gpu_kernel)]
+// Check we error before unsupported ABIs reach codegen stages.
+
+fn main() {
+    let a = unsafe { core::mem::transmute::<usize, extern "gpu-kernel" fn(i32)>(4) }(2);
+    //~^ ERROR E0570
+}

tests/ui/abi/unsupported-abi-transmute.rs

@@ -0,0 +1,9 @@
+error[E0570]: `"gpu-kernel"` is not a supported ABI for the current target
+  --> $DIR/unsupported-abi-transmute.rs:5:59
+   |
+LL |     let a = unsafe { core::mem::transmute::<usize, extern "gpu-kernel" fn(i32)>(4) }(2);
+   |                                                           ^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0570`.