Use less magical numbers for regular expression flags

Author: kddnewton

lib/yarp.rb

@@ -432,7 +432,7 @@ class InterpolatedRegularExpressionNode < Node
     # Returns a numeric value that represents the flags that were used to create
     # the regular expression.
     def options
-      o = flags & 0b111
+      o = flags & (RegularExpressionFlags::IGNORE_CASE | RegularExpressionFlags::EXTENDED | RegularExpressionFlags::MULTI_LINE)
       o |= Regexp::FIXEDENCODING if flags.anybits?(RegularExpressionFlags::EUC_JP | RegularExpressionFlags::WINDOWS_31J | RegularExpressionFlags::UTF_8)
       o |= Regexp::NOENCODING if flags.anybits?(RegularExpressionFlags::ASCII_8BIT)
       o
@@ -450,7 +450,7 @@ class RegularExpressionNode < Node
     # Returns a numeric value that represents the flags that were used to create
     # the regular expression.
     def options
-      o = flags & 0b111
+      o = flags & (RegularExpressionFlags::IGNORE_CASE | RegularExpressionFlags::EXTENDED | RegularExpressionFlags::MULTI_LINE)
       o |= Regexp::FIXEDENCODING if flags.anybits?(RegularExpressionFlags::EUC_JP | RegularExpressionFlags::WINDOWS_31J | RegularExpressionFlags::UTF_8)
       o |= Regexp::NOENCODING if flags.anybits?(RegularExpressionFlags::ASCII_8BIT)
       o