PR target/49868

	PR target/49868
	PR target/50887
	* doc/extend.texi (Named Address Spaces): Split into subsections.
	(AVR Named Address Spaces): New subsection.
	(M32C Named Address Spaces): New subsection.
	(RL78 Named Address Spaces): New subsection.
	(SPU Named Address Spaces): New subsection.
	(Variable Attributes): New anchor "AVR Variable Attributes".
	(AVR Variable Attributes): Rewrite and avoid wording
	"address space" in this context.
	* doc/invoke.texi (AVR Options): Rewrite and add documentation
	for -maccumulate-args, -mbranch-cost=, -mrelax, -mshort-calls.
	(AVR Built-in Macros): New subsubsection therein.
	* doc/md.texi (AVR constraints): Remove "C04", "R".

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@183336 138bc75d-0d04-0410-961f-82ee72b054a4