* doc/gty.texi (GGC Roots): Clarify that the list of syntaxes
is exhaustive.
(Files): Improve documentation on generated source files.
* doc/extend.texi (Translation implementation): Document what
diagnostics look like.
(Identifiers implementation): Document that there's normally no
limit on identifier names.
(Integers implementation): Document two's complement.
(Hints implementation): Document that GCC honours 'inline', mostly.
(Preprocessing directives implementation): Document that GCC
requires the current time.
From-SVN: r55857
