Make UBSan warnings fatal and fix the existing ones

The warnings were (all signed integer overflow):
webrtc/common_audio/signal_processing/levinson_durbin.c:46:25
12 * 268435456 cannot be represented in type 'int'
webrtc/modules/audio_processing/aecm/aecm_core.cc:930:69
522240 * 6115 cannot be represented in type 'int'
webrtc/modules/audio_processing/aecm/aecm_core_c.cc:455:36
72293096 * 50 cannot be represented in type 'int'
webrtc/modules/pacing/alr_detector.cc:70:48
1000000000 * 65 cannot be represented in type 'int'
webrtc/modules/rtp_rtcp/source/rtp_sender.cc:947:20
1929277286 + 321546521 cannot be represented in type 'int'

BUG=webrtc:8195

Review-Url: https://codereview.webrtc.org/3005003002
Cr-Original-Commit-Position: refs/heads/master@{#19670}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: ba09f79ba31c543d0dcf3a6d824992685087005a
3 files changed