Added boundary check for array access as a short-term way of fixing the bug of out-of-bounds reads into the array
Added boundary check for array access as a short-term way of fixing the bug of out-of-bounds reads into the array

BUG=chromium:529527, chromium:529552

Review URL: https://codereview.webrtc.org/1338993003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#9930}

TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc