When using pgx, map numeric types to pgtype.Numeric (sqlc-dev#1143)

* endtoend: Consolidate test cases

* codegen/golang: numeric -> pgtype.Numeric for pgx

Fix the regenration script to always pass the `experimental` flag.

internal/codegen/golang/imports.go

@@ -136,6 +136,7 @@ var pgtypeTypes = map[string]struct{}{
 	"pgtype.CIDR":    {},
 	"pgtype.Inet":    {},
 	"pgtype.Macaddr": {},
+	"pgtype.Numeric": {},
 }
 
 var pqtypeTypes = map[string]struct{}{

internal/codegen/golang/postgresql_type.go

@@ -58,6 +58,9 @@ func postgresType(r *compiler.Result, col *compiler.Column, settings config.Comb
 		return "sql.NullFloat64" // TODO: Change to sql.NullFloat32 after updating the go.mod file
 
 	case "numeric", "pg_catalog.numeric", "money":
+		if driver == SQLDriverPGXV4 {
+			return "pgtype.Numeric"
+		}
 		// Since the Go standard library does not have a decimal type, lib/pq
 		// returns numerics as strings.
 		//

internal/endtoend/testdata/datatype/pgx/sql/net-types.sql

@@ -0,0 +1,13 @@
+-- Network Address Types
+-- https://www.postgresql.org/docs/current/datatype-net-types.html
+CREATE TABLE dt_net_types (
+  a  inet,
+  b  cidr,
+  c  macaddr
+);
+
+CREATE TABLE dt_net_types_not_null (
+  a  inet NOT NULL,
+  b  cidr NOT NULL,
+  c  macaddr NOT NULL
+);

internal/endtoend/testdata/datatype/stdlib/sql/net-types.sql

@@ -0,0 +1,13 @@
+-- Network Address Types
+-- https://www.postgresql.org/docs/current/datatype-net-types.html
+CREATE TABLE dt_net_types (
+  a  inet,
+  b  cidr,
+  c  macaddr
+);
+
+CREATE TABLE dt_net_types_not_null (
+  a  inet NOT NULL,
+  b  cidr NOT NULL,
+  c  macaddr NOT NULL
+);