[gl] Fix 'inout' variable qualification + complex readback

- Can use variables with both input and output qualities
- Allow readback of complex structures. 3 phases:
   - host_pack_tmp_alloc: custom expression to allocate aligned
     temporaries for the output structs
   - host_pack: custom expression to pack into stream (losing
     alignment)
   - guest_unpack: custom expression to unpack into object on guest
     (regaining alignment)

Change-Id: I9073325efe6847762e8b2d42fd9803d81ff67374
23 files changed
tree: 2f15143e496a89fae3780b23559c07d7e2cf776d
  1. android/
  2. host/
  3. .gitignore