Support kernels with version >= 3.10

Newer Android Linux kernels modify the way certain devices are
named, i.e.:

  /dev/qemu_pipe is renamed as /dev/goldfish_pipe.
  /dev/ttyS<num> is renamed as /dev/ttyGF<num>

This patch adds support code to the emulator to deal with this
as transparently as possible:

1) Add a new hardware property 'kernel.newDeviceNaming', a string
   which can only take the values 'autodetect', 'no', and 'yes'.

2) Support code to probe the type of a kernel image.
   IMPORTANT: The kernel implementation depends on the host
   /usr/bin/file to properly recognize kernel files and extract
   their version number. This really only works on Linux and
   OS X, and only for x86 and x86_64 kernel images.

   A future patch will implement more robust detection by
   essentially doing its own probing through libmagic or equivalent.

   Note that there doesn't seem to be any existing libmagic rules
   to recognize ARM and MIPS kernel images at the moment :-(

   See android/kernel/kernel_utils*

3) Modify the emulator startup code to perform auto-detection
   when possible (broken on Windows, and non Intel archs, see
   comment above).

4) Modify the kernel command line generation to handle the new
   TTY device naming

5) Modify the Goldfish pipe virtual device implementation
   (since the device name presented to the kernel also changed).

This should be enough to auto-detect Linux 3.10+ x86_64 kernel
images on Linux.

Change-Id: Ied517f8a1fdeb18d84fa9a12ebcdc3daa1f41d9a
diff --git a/Makefile.tests b/Makefile.tests
index 2c4b28c..7181c41 100644
--- a/Makefile.tests
+++ b/Makefile.tests
@@ -18,6 +18,7 @@
   android/base/String_unittest.cpp \
   android/base/StringView_unittest.cpp \
   android/filesystems/ext4_utils_unittest.cpp \
+  android/kernel/kernel_utils_unittest.cpp \
 
 $(call start-emulator-program, emulator_unittests)
 LOCAL_C_INCLUDES += $(EMULATOR_GTEST_INCLUDES)