am e57d8918: merge from open-source master

Merge commit 'e57d89186def9dfabe39cec7a91397079514dc2a' into kraken

* commit 'e57d89186def9dfabe39cec7a91397079514dc2a':
  fix sim build
  Fix LDM addressing mode disassembly
  Add documentation for some adb environmental variables.
  NEON shortcut for flat colour blending into 16-bit
  Adds UXTB16 support to Pixelflinger