rustc_typeck: don't expect rvalues to have unsized types.
syntax: format: remove unused method_statics field.
syntax: format: put static arrays in their own blocks to avoid needing a wrapper block.
syntax: turn the match-call generated by format_args inside-out.
syntax: use std::string::String unqualified in format.
syntax: change format_args! to produce fmt::Arguments instead of calling a function with them.
Fallout of changing format_args!(f, args) to f(format_args!(args)).