Ruby

• vm_core.h (rb_location_t): fix type and field name.
  (1) rename rb_location_t to rb_iseq_location_t.
  (2) rename field names of rb_iseq_location_t to adjust
  RubyVM::Backtrace::Location methods.
  (2-1) filename -> path
  (2-2) filepath -> absolute_path
  (2-3) basename -> base_label
  (2-4) name -> label
  (3) rename filed name rb_iseq_location_t#line_no to
  rb_iseq_location_t#first_lineno to clear purpose of this field.
  (4) The field names rb_binding_t#(filename|line_no) are also renamed
  to rb_binding_t#(path|first_lineno).
• compile.c: apply above changes.
• iseq.c: ditto.
• proc.c: ditto.
• vm*.c: ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35899 b2dd03c8-39d4-4d8f-98ff-823fe69b080e