Add method_idx output to dexdump and dexlayout

Includes method_idx when dumping methods. To keeep the default output
the same, this field is only displayed when the -h option is given,
which is the option that also controls when the class_idx field is
displayed.

Test: m test-art-host-gtest
Change-Id: I6a71d2ecd29e50df506e97bb4c08c94a0b4c5a6a
2 files changed