builder: link stack probes on Windows amd64 and arm64

Go 1.27 packages can emit stack probes on Windows amd64 and arm64.
Link the compiler-rt stack probe builtins and use compiler-rt for those
targets so these packages build.

compileopts/target.go

@@ -475,10 +475,12 @@ func defaultTarget(options *Options) (*TargetSpec, error) {
 				"-m", "i386pep",
 				"--image-base", "0x400000",
 			)
+			spec.RTLib = "compiler-rt"
 		case "arm64":
 			spec.LDFlags = append(spec.LDFlags,
 				"-m", "arm64pe",
 			)
+			spec.RTLib = "compiler-rt"
 		}
 		spec.LDFlags = append(spec.LDFlags,
 			"-Bdynamic",