Drop old enum syntax. Comma / semicolon are now a syntactic part of enum entry.

Comma must present now between enum entries, semicolon between last entry & first member, constructor calls must be without colons / specifiers.
A swarm of tests fixed accordingly.

compiler/testData/psi/CommentsBinding.txt

@@ -352,6 +352,7 @@ JetFile: CommentsBinding.kt
       ENUM_ENTRY
         OBJECT_DECLARATION_NAME
           PsiElement(IDENTIFIER)('A')
+        PsiElement(COMMA)(',')
         PsiWhiteSpace(' ')
         PsiComment(EOL_COMMENT)('// this is A')
       PsiWhiteSpace('\n    ')
@@ -364,12 +365,14 @@ JetFile: CommentsBinding.kt
         PsiWhiteSpace(' ')
         OBJECT_DECLARATION_NAME
           PsiElement(IDENTIFIER)('B')
+        PsiElement(COMMA)(',')
       PsiWhiteSpace('\n    ')
       ENUM_ENTRY
         PsiComment(BLOCK_COMMENT)('/* And this is C */')
         PsiWhiteSpace(' ')
         OBJECT_DECLARATION_NAME
           PsiElement(IDENTIFIER)('C')
+        PsiElement(COMMA)(',')
       PsiWhiteSpace('\n    ')
       ENUM_ENTRY
         KDoc