[Bug #19619] Preserve numbered parameters context

	Preserve numbered parameters context across method definitions

	[Bug #20517] Make a multibyte character one token at meta escape

	[Bug #20030] dispatch invalid escaped character without ignoring it

This reverts commit 24dd529750c08b5603fb418a4f34998b9bf6c8f9.

	[Bug #19973] Warn duplicated keyword arguments after keyword splat

	---
	 parse.y                  | 11 +++++++----
	 test/ruby/test_syntax.rb |  6 ++++++
	 2 files changed, 13 insertions(+), 4 deletions(-)

	[Bug #19924] Source code should be unsigned char stream

	Use `peekc` or `nextc` to fetch the next character, instead of reading
	from `lex.pcur` directly, for compilers that plain char is signed.
	---
	 parse.y                 | 10 +++++-----
	 test/ruby/test_parse.rb |  2 ++
	 2 files changed, 7 insertions(+), 5 deletions(-)

	[Bug #19788] Use the result of `tCOLON2` event

	---
	 parse.y                            | 16 ++++++++--------
	 test/ripper/test_parser_events.rb  | 17 +++++++++++++++++
	 test/ripper/test_scanner_events.rb |  5 +++++
	 3 files changed, 30 insertions(+), 8 deletions(-)

	Fix memory leak for incomplete lambdas

	[Bug #19836]

	The parser does not free the chain of `struct vtable`, which causes
	memory leaks.

	The following script reproduces this issue:

	```
	10.times do
	  100_000.times do
	    Ripper.parse("-> {")
	  end

	  puts `ps -o rss= -p #{$$}`
	end
	```
	---
	 parse.y                    | 24 ++++++++++++++----------
	 test/ripper/test_ripper.rb |  7 +++++++
	 2 files changed, 21 insertions(+), 10 deletions(-)

	Fix memory leak in parser for incomplete tokens

	[Bug #19835]

	The parser does not free the `tbl` of the `struct vtable` when there are
	leftover `lvtbl` in the parser. This causes a memory leak.

	The following script reproduces this issue:

	```
	10.times do
	  100_000.times do
	    Ripper.parse("class Foo")
	  end

	  puts `ps -o rss= -p #{$$}`
	end
	```
	---
	 parse.y                    | 42 ++++++++++++++++++++++++++++--------------
	 test/ripper/test_ripper.rb |  7 +++++++
	 2 files changed, 35 insertions(+), 14 deletions(-)

	[Bug #19025] Numbered parameter names are always local variables

	---
	 parse.y                  | 2 +-
	 test/ruby/test_syntax.rb | 1 +
	 2 files changed, 2 insertions(+), 1 deletion(-)