This can happen when a syntactically incorrect text is passed to a
merl:qquote/2,/3 call.

The parse transform optimizes calls to some functions in merl by
converting strings into templates at compile time. If this evaluation
fails (in eval_call/4 - for example because of a sytanx error in the
parsed text) the original function call should be kept unchanged.
However in case of qquote/3 the call is converted into a combination of
quote/2 and subst/2, but upon failure the original qquote/3 call is
substituted into the wrong place. E.g.:

this expression
  merl:qquote(Pos, Text, Env)

is first converted to
  merl:subst(merl:quote(Pos, Text), Env)

then if evaluating the quote call fails into
  merl:subst(merl:qquote(Pos, Text, Env), Env)

and the expansion is run again on the internal qquote/3 argument
resulting in an infinite loop.

This is now fixed so in case of failure the original qquote/3 call is kept.

Extract specs och types from source files, which ensures that
seealso:s referring to, for example, erl_parse:abstract_form(), are
assigned working links.

See also http://bugs.erlang.org/browse/ERL-151.

* hasse/dialyzer/improve_from_form/OTP-13547:
  Update primary bootstrap
  stdlib: Correct types and specs
  dialyzer: Minor adjustments
  dialyzer: Suppress unmatched_return for send/2
  dialyzer: Improve the translation of forms to types
  dialyzer: Use a cache when translating forms to types
  dialyzer: Prepare erl_types:t_from_form() for a cache
  dialyzer: Optimize erl_types:t_form_form()
  dialyzer: Correct types
  syntax_tools: Correct types
  erts: Correct character repr in doc of the abstract format
  stdlib: Correct types and specs

It is possible that '...' is added later (OTP 20.0), but for now we
are not sure of all details.