Update supported go version to 1.18.* and 1.19.*

Client: go

Also provide generic version of Pointer helper function.
diff --git a/lib/go/test/fuzz/go.mod b/lib/go/test/fuzz/go.mod
index 3cefa02..c9ef373 100644
--- a/lib/go/test/fuzz/go.mod
+++ b/lib/go/test/fuzz/go.mod
@@ -1,6 +1,6 @@
 module github.com/apache/thrift/lib/go/test/fuzz
 
-go 1.16
+go 1.18
 
 replace github.com/apache/thrift => ../../../../
 
diff --git a/lib/go/thrift/pointerize.go b/lib/go/thrift/pointerize.go
index fb564ea..e200c68 100644
--- a/lib/go/thrift/pointerize.go
+++ b/lib/go/thrift/pointerize.go
@@ -19,6 +19,12 @@
 
 package thrift
 
+// Pointer is the generic (type parameter) version of the helper function that
+// converts types to pointer types.
+func Pointer[T any](v T) *T {
+	return &v
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // This file is home to helpers that convert from various base types to
 // respective pointer types. This is necessary because Go does not permit