Same for go

Fix #2752

pmd-go/src/main/antlr4/net/sourceforge/pmd/lang/go/antlr4/Golang.g4

@@ -1264,11 +1264,10 @@ fragment UNICODE_LETTER
  | [\u31A0-\u31B7]
  | [\u3400]
  | [\u4DB5]
- | [\u4E00]
+ | [\u4E00-\u9EA5]
- | [\u9FA5]
  | [\uA000-\uA48C]
- | [\uAC00]
+ | [\uA490-\uABFF]
- | [\uD7A3]
+ | [\uAC00-\uD7AF]
  | [\uF900-\uFA2D]
  | [\uFB00-\uFB06]
  | [\uFB13-\uFB17]

pmd-go/src/test/java/net/sourceforge/pmd/cpd/GoTokenizerTest.java

@@ -40,4 +40,11 @@ public class GoTokenizerTest extends CpdTextComparisonTest {
     public void testIssue1751() {
         doTest("issue-1751");
     }
+
+    @Test
+    public void testUnicode() {
+        // https://github.com/pmd/pmd/issues/2752
+        doTest("sample_unicode");
+    }
+
 }

pmd-go/src/test/resources/net/sourceforge/pmd/lang/go/cpd/testdata/sample_unicode.go

@@ -0,0 +1,20 @@
+func main() {
+	//string底层是一个byte数组，因此string也可以进行切片操作
+	str := "hello world"//string是不可变的
+	slice := str[4:]
+	fmt.Println(slice)
+
+	//若要对string进行修改需要将string修改为byte或rune的切片在操作
+	//但是转为byte无法进行中文操作
+	bytes := []byte(str)
+	bytes[2] = 'x'
+	str = string(bytes)
+	fmt.Println(str)
+
+	//转换成rune可以对中文进行操作
+	runes := []rune(str)
+	runes[0] = '哈'
+	str = string(runes)
+	fmt.Println(str)
+
+}

pmd-go/src/test/resources/net/sourceforge/pmd/lang/go/cpd/testdata/sample_unicode.txt

@@ -0,0 +1,89 @@
+    [Image] or [Truncated image[            Bcol      Ecol
+L1
+    [func]                                  1         4
+    [main]                                  6         9
+    [(]                                     10        10
+    [)]                                     11        11
+    [{]                                     13        13
+L3
+    [str]                                   2         4
+    [:=]                                    6         7
+    ["hello world"]                         9         21
+L4
+    [slice]                                 2         6
+    [:=]                                    8         9
+    [str]                                   11        13
+    [\[]                                    14        14
+    [4]                                     15        15
+    [:]                                     16        16
+    [\]]                                    17        17
+L5
+    [fmt]                                   2         4
+    [.]                                     5         5
+    [Println]                               6         12
+    [(]                                     13        13
+    [slice]                                 14        18
+    [)]                                     19        19
+L9
+    [bytes]                                 2         6
+    [:=]                                    8         9
+    [\[]                                    11        11
+    [\]]                                    12        12
+    [byte]                                  13        16
+    [(]                                     17        17
+    [str]                                   18        20
+    [)]                                     21        21
+L10
+    [bytes]                                 2         6
+    [\[]                                    7         7
+    [2]                                     8         8
+    [\]]                                    9         9
+    [=]                                     11        11
+    ['x']                                   13        15
+L11
+    [str]                                   2         4
+    [=]                                     6         6
+    [string]                                8         13
+    [(]                                     14        14
+    [bytes]                                 15        19
+    [)]                                     20        20
+L12
+    [fmt]                                   2         4
+    [.]                                     5         5
+    [Println]                               6         12
+    [(]                                     13        13
+    [str]                                   14        16
+    [)]                                     17        17
+L15
+    [runes]                                 2         6
+    [:=]                                    8         9
+    [\[]                                    11        11
+    [\]]                                    12        12
+    [rune]                                  13        16
+    [(]                                     17        17
+    [str]                                   18        20
+    [)]                                     21        21
+L16
+    [runes]                                 2         6
+    [\[]                                    7         7
+    [0]                                     8         8
+    [\]]                                    9         9
+    [=]                                     11        11
+    ['哈']                                   13        15
+L17
+    [str]                                   2         4
+    [=]                                     6         6
+    [string]                                8         13
+    [(]                                     14        14
+    [runes]                                 15        19
+    [)]                                     20        20
+L18
+    [fmt]                                   2         4
+    [.]                                     5         5
+    [Println]                               6         12
+    [(]                                     13        13
+    [str]                                   14        16
+    [)]                                     17        17
+L20
+    [}]                                     1         1
+EOF