emulator: opengl: 'large' buffer optimization

This patch modifies the guest encoding libraries to avoid
un-necessary copies when sending large buffers (e.g. pixels)
to the host. Instead, the data is sent directly through a
new IOStream method (writeFully()).

On my machine, this improves the NenaMark2 benchmark
(from 50.8 to 57.1 fps). More importantly, this speeds up
the display of non-GL surfaces too, which are sent through
the special rcUpdateColorBuffer() function in gralloc_goldfish.

This is noticeable in many parts of the UI (e.g. when scrolling
through lists).

To tag a given parameter, use the new 'isLarge' variable flag
in the protocol .attrib file.

Implemented for the following encoding functions:

  rcUpdateColorBuffer
  glTexSubImage2D
  glTexImage2Di
  glBufferData
  glBufferSubData
  glCompressedTexImage2D
  glCompressedTexSubImage2D
  glTexImage3DOES
  glTexSubImage3DOES
  glCompressedTexImage3DOES
  glCompressedTexSubImage3DOES

+ Optimize the auto-generated encoder functions to avoid
  repeated function calls (for size computations).

Change-Id: I13a02607b606c40cd05984cd2051b1f3424bc2d0

tools/emulator/opengl/system/renderControl_enc/renderControl.attrib

@@ -26,10 +26,10 @@ rcGetConfigs
 
 rcChooseConfig
     dir attribs in
-	len attribs attribs_size
-	dir configs out
+    len attribs attribs_size
+    dir configs out
     var_flag configs nullAllowed
-	len configs configs_size*sizeof(uint32_t)
+    len configs configs_size*sizeof(uint32_t)
 
 rcReadColorBuffer
     dir pixels out
@@ -38,3 +38,4 @@ rcReadColorBuffer
 rcUpdateColorBuffer
     dir pixels in
     len pixels (((glUtilsPixelBitSize(format, type) * width) >> 3) * height)
+    var_flag pixels isLarge