GROOVY-8831: Add instance methods from `String` to `GString`(closes #806)
GROOVY-8831: Add instance methods from `String` to `GString`(closes #806)

jwagenleitner/groovy,russel/groovy,armsargis/groovy,russel/groovy,jwagenleitner/incubator-groovy,russel/incubator-groovy,shils/incubator-groovy,shils/incubator-groovy,paulk-asert/incubator-groovy,jwagenleitner/groovy,apache/groovy,russel/incubator-groovy,shils/groovy,paulk-asert/groovy,armsargis/groovy,jwagenleitner/groovy,jwagenleitner/incubator-groovy,jwagenleitner/groovy,jwagenleitner/incubator-groovy,apache/incubator-groovy,apache/groovy,shils/incubator-groovy,jwagenleitner/incubator-groovy,paulk-asert/groovy,paulk-asert/groovy,apache/incubator-groovy,apache/incubator-groovy,paulk-asert/incubator-groovy,shils/groovy,russel/incubator-groovy,shils/incubator-groovy,shils/groovy,shils/groovy,paulk-asert/groovy,apache/incubator-groovy,traneHead/groovy-core,apache/groovy,paulk-asert/incubator-groovy,russel/incubator-groovy,traneHead/groovy-core,russel/groovy,paulk-asert/incubator-groovy,armsargis/groovy,apache/groovy,armsargis/groovy,traneHead/groovy-core,paulk-asert/incubator-groovy,traneHead/groovy-core,russel/groovy