[ruby/rdoc] Parse also InitVM-prefixed functions

Initialization depending on VM is separated.

https://github.com/ruby/rdoc/commit/030d10fccd

lib/rdoc/parser/c.rb

@@ -720,7 +720,7 @@ class RDoc::Parser::C < RDoc::Parser
         ((?>/\*.*?\*/\s+))
         (static\s+)?
         void\s+
-        Init_#{class_name}\s*(?:_\(\s*)?\(\s*(?:void\s*)?\)%xmi then
+        Init(?:VM)?_(?i:#{class_name})\s*(?:_\(\s*)?\(\s*(?:void\s*)?\)%xm then
       comment = $1.sub(%r%Document-(?:class|module):\s+#{class_name}%, '')
     elsif @content =~ %r%Document-(?:class|module):\s+#{class_name}\s*?
                          (?:<\s+[:,\w]+)?\n((?>.*?\*/))%xm then

test/rdoc/test_rdoc_parser_c.rb

@@ -857,6 +857,23 @@ Init_Foo(void) {
     assert_equal "a comment for class Foo", klass.comment.text
   end
 
+
+  def test_find_class_comment_initvm
+    content = <<-EOF
+/*
+ * a comment for class Foo
+ */
+void
+InitVM_Foo(void) {
+  VALUE foo = rb_define_class("Foo", rb_cObject);
+}
+    EOF
+
+    klass = util_get_class content, 'foo'
+
+    assert_equal "a comment for class Foo", klass.comment.text
+  end
+
   def test_find_class_comment_define_class
     content = <<-EOF
 /*