* nnheader.el (nnheader-find-file-noselect): Use
`find-file-noselect-as-coding-system' (renamed from
`find-file-noselect-as-specified-coding-system').
* nnmail.el (nnmail-find-file): Use `insert-file-contents-as-coding-system'
(renamed from `insert-file-contents-as-specified-coding-system').
* nnheader.el (nnheader-insert-file-contents): Likewise.
* gnus-start.el (gnus-save-newsrc-file): Use `write-region-as-coding-system'
(renamed from `write-region-as-specified-coding-system').
(gnus-read-newsrc-el-file): Use `insert-file-contents-as-coding-system'
(renamed from `insert-file-contents-as-specified-coding-system').
* gnus-cache.el (gnus-cache-save-buffers): Use
`gnus-write-buffer-as-coding-system' (renamed from
`gnus-write-buffer-as-specified-coding-system').
* gnus-util.el (gnus-write-buffer-as-coding-system): Renamed from
`gnus-write-buffer-as-specified-coding-system'.
* nnmail.el (nnmail-write-region): Use `write-region-as-coding-system'
(renamed from `write-region-as-specified-coding-system').
* gnus-start.el (gnus-save-newsrc-file): Likewise.
* gnus-agent.el (gnus-agent-expire): Likewise.
(gnus-agent-fetch-headers): Likewise.
(gnus-agent-flush-cache): Likewise.
(gnus-agent-fetch-articles): Likewise.
(gnus-agent-save-history): Likewise.
(gnus-agent-save-groups): Likewise.
(gnus-agent-save-active): Likewise.