Control Flow Integrity [1] indirect call checking verifies that function
pointers only call valid functions with a matching type signature. This
change eliminates function pointer casts that were causing cfi-icall
failures.
[1] https://www.chromium.org/developers/testing/control-flow-integrity
BUG=chromium:827826
Change-Id: I5db021d06390a6cefd670fdd2f0d34c9e530465e
(cherry picked from commit 978eec2507e3b5110bd1d2a408fa27a8f7e702cf)
* regarding alpha_data_ used for testing.
alpha_data_!=NULL is as close a good test as we'll get.
* regarding filter-strength / sharpness forcing
no practical use (can be done during encode cycles,
for experimentation)
* regarding a 'less-complex' filtering:
no practical use so far. Next version!
Change-Id: If2dfff5818552a7d3e7c23ac08d64fe6d270229c
this avoids duplicates between these trees and dsp/, e.g., enc/tree.c,
dec/tree.c, making pulling the whole library source tree into one target
possible
BUG=webp:279
Change-Id: I060a614833c7c24ddd37bf641702ae6a5eef1775
