Clarify __END__ comment

Author: kddnewton

include/prism/parser.h

@@ -557,7 +557,11 @@ struct pm_parser {
     /** The list of magic comments that have been found while parsing. */
     pm_list_t magic_comment_list;
 
-    /** The optional location of the __END__ keyword and its contents. */
+    /**
+     * An optional location that represents the location of the __END__ marker
+     * and the rest of the content of the file. This content is loaded into the
+     * DATA constant when the file being parsed is the main file being executed.
+     */
     pm_location_t data_loc;
 
     /** The list of warnings that have been found while parsing. */

lib/prism/parse_result.rb

@@ -369,9 +369,9 @@ class ParseResult
     # The list of magic comments that were encountered during parsing.
     attr_reader :magic_comments
 
-    # An optional location that represents the location of the content after the
-    # __END__ marker. This content is loaded into the DATA constant when the
-    # file being parsed is the main file being executed.
+    # An optional location that represents the location of the __END__ marker
+    # and the rest of the content of the file. This content is loaded into the
+    # DATA constant when the file being parsed is the main file being executed.
     attr_reader :data_loc
 
     # The list of errors that were generated during parsing.