Ruby: Add regex group tests

Author: hvitved

ruby/ql/test/library-tests/regexp/regexp.expected

@@ -0,0 +1,13 @@
+groupName
+| regexp.rb:52:2:52:11 | (?<id>\\w+) | d |
+| regexp.rb:53:2:53:12 | (?'foo'fo+) | oo |
+| regexp.rb:57:2:57:11 | (?<qux>q+) | ux |
+groupNumber
+| regexp.rb:46:2:46:6 | (foo) | 1 |
+| regexp.rb:47:4:47:8 | (o\|b) | 1 |
+| regexp.rb:48:2:48:9 | (a\|b\|cd) | 1 |
+| regexp.rb:49:2:49:7 | (?::+) | 1 |
+| regexp.rb:52:2:52:11 | (?<id>\\w+) | 1 |
+| regexp.rb:53:2:53:12 | (?'foo'fo+) | 1 |
+| regexp.rb:56:2:56:5 | (a+) | 1 |
+| regexp.rb:57:2:57:11 | (?<qux>q+) | 1 |

ruby/ql/test/library-tests/regexp/regexp.ql

@@ -0,0 +1,5 @@
+import codeql.ruby.security.performance.RegExpTreeView
+
+query predicate groupName(RegExpGroup g, string name) { name = g.getName() }
+
+query predicate groupNumber(RegExpGroup g, int number) { number = g.getNumber() }