Add support for preferred arch symlinks

Add a symlink_preferred_arch property to binaries to allow compiling the
binary for multiple architectures and then creating a symlink to the
preferred archicture, for example dalvikvm32 and dalvikvm64, with
dalvikvm symlinked to dalvikvm64.

Test: mmma -j art/dalvikvm
Change-Id: Ied15f2be9d52c01006fe8ac207c175b78558eab1
diff --git a/cc/androidmk.go b/cc/androidmk.go
index 283fe27..d4965d8 100644
--- a/cc/androidmk.go
+++ b/cc/androidmk.go
@@ -125,6 +125,7 @@
 }
 
 func (binary *binaryDecorator) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) {
+	ctx.subAndroidMk(ret, binary.baseInstaller)
 	ctx.subAndroidMk(ret, &binary.stripper)
 
 	ret.Class = "EXECUTABLES"