build/tools.atree: Move x86-specific changes to tools.x86.atree

Unfortunately, the latest x86-specific changes to tools.atree break
internal Android builds that depend on this file.

This change moves the changes to a different file that is only
parsed for x86-specific SDK builds (sdk_x86-eng).

It depends on https://review.source.android.com/#change,21957
to allow the AOSP build to pick up tools.x86.atree properly.

Change-Id: I163d7fb43aa06609d9b0e4bfbaf56311958ea25e
diff --git a/build/tools.atree b/build/tools.atree
index db3367c..208f6f7 100644
--- a/build/tools.atree
+++ b/build/tools.atree
@@ -40,11 +40,10 @@
 bin/zipalign     tools/zipalign
 
 # emulator
-bin/emulator tools/emulator-arm
-bin/emulator-x86   tools/emulator-x86
+# note: the following line should better to to tools.arm.atree
+# but is kept here to avoid breaking internal branches.
+bin/emulator  tools/emulator-arm
 sdk/emulator/snapshot/snapshots.img tools/lib/emulator/snapshots.img
-usr/share/pc-bios/bios.bin   tools/lib/pc-bios/bios.bin
-usr/share/pc-bios/vgabios-cirrus.bin   tools/lib/pc-bios/vgabios-cirrus.bin
 
 # Java-Based SDK Tools
 bin/ddms            tools/ddms