Docs: Fix some too-long lines in Texinfo manual.

Docs: Fix some too-long lines in Texinfo manual.

gcc/ChangeLog:
	* doc/extend.texi (Common Function Attributes) <access>: Fix bad
	line breaks in examples.
	<malloc>: Fix bad line breaks in running text, also copy-edit
	for consistency.
	(Extended Asm) <Generic Operand Modifiers>: Fix @multitable width.
	* doc/invoke.texi (Option Summary) <Developer Options>: Fix misplaced
	@gol.
	(C++ Dialect Options) <-fcontracts>: Add line break in example.
	<-Wctad-maybe-unsupported>: Likewise.
	<-Winvalid-constexpr>: Likewise.
	(Warning Options) <-Wdangling-pointer>: Likewise.
	<-Winterference-size>: Likewise.
	<-Wvla-parameter>: Likewise.
	(Static Analyzer Options): Fix bad line breaks in running text,
	plus add some missing markup.
	(Optimize Options) <openacc-privatization>: Fix more bad line
	breaks in running text.