This CL changes so that the fft4g code is built as C++.
The CL also
-adds namespaces
-removes unused code.
To simplify the review, the CL is partitioned into different patchsets
where each comprising of one step in the modification of the code
(e.g., patch set 1 performs the renaming of the .c files to .cc).
Bug: webrtc:5298
Change-Id: I1dba78cc07c48622888be7b6f49a506795bc22ed
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/171100
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30841}
e1b7af9f94