Add test case with rest variable and no prefix elements

ruby/ql/test/library-tests/ast/Ast.expected

@@ -864,6 +864,7 @@ control/cases.rb:
 #   67|       getPattern: [ArrayPattern] [ ..., * ]
 #   68|     getBranch: [InClause] in ... then ...
 #   68|       getPattern: [ArrayPattern] [ ..., * ]
+#   68|         getRestVariableAccess: [LocalVariableAccess] x
 #   68|         getSuffixElement: [IntegerLiteral] 3
 #   68|         getSuffixElement: [IntegerLiteral] 4
 #   69|     getBranch: [InClause] in ... then ...

ruby/ql/test/library-tests/ast/ValueText.expected

@@ -156,8 +156,8 @@
 | control/cases.rb:65:13:65:13 | 3 | 3 |
 | control/cases.rb:66:7:66:7 | 1 | 1 |
 | control/cases.rb:66:14:66:14 | 3 | 3 |
-| control/cases.rb:68:10:68:10 | 3 | 3 |
-| control/cases.rb:68:13:68:13 | 4 | 4 |
+| control/cases.rb:68:11:68:11 | 3 | 3 |
+| control/cases.rb:68:14:68:14 | 4 | 4 |
 | control/cases.rb:69:10:69:10 | 3 | 3 |
 | control/cases.rb:70:11:70:11 | 3 | 3 |
 | control/cases.rb:71:7:71:7 | :a | a |

ruby/ql/test/library-tests/ast/control/CaseExpr.expected

@@ -67,7 +67,7 @@ caseAllBranches
 | cases.rb:39:1:80:3 | case ... | 25 | cases.rb:65:3:65:18 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 26 | cases.rb:66:3:66:16 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 27 | cases.rb:67:3:67:9 | in ... then ... |
-| cases.rb:39:1:80:3 | case ... | 28 | cases.rb:68:3:68:15 | in ... then ... |
+| cases.rb:39:1:80:3 | case ... | 28 | cases.rb:68:3:68:16 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 29 | cases.rb:69:3:69:15 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 30 | cases.rb:70:3:70:17 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 31 | cases.rb:71:3:71:10 | in ... then ... |

ruby/ql/test/library-tests/ast/control/cases.rb

@@ -65,7 +65,7 @@ case expr
   in [1, 2, 3, *] 
   in [1, *x, 3] 
   in [*] 
-  in [*, 3, 4] 
+  in [*x, 3, 4] 
   in [*, 3, *] 
   in [*a, 3, *b] 
   in {a:}