Add support for unsigned integer literals in TextMate grammar (#453)

Author: a-stewart

grammars/Kotlin.tmLanguage.json

@@ -503,11 +503,11 @@
             ]
         },
         "decimal-literal": {
-            "match": "\\b\\d[\\d_]*(\\.[\\d_]+)?((e|E)\\d+)?(L|F|f)?\\b",
+            "match": "\\b\\d[\\d_]*(\\.[\\d_]+)?((e|E)\\d+)?(u|U)?(L|F|f)?\\b",
             "name": "constant.numeric.decimal.kotlin"
         },
         "hex-literal": {
-            "match": "0(x|X)[A-Fa-f0-9][A-Fa-f0-9_]*",
+            "match": "0(x|X)[A-Fa-f0-9][A-Fa-f0-9_]*(u|U)?",
             "name": "constant.numeric.hex.kotlin"
         },
         "binary-literal": {