Let header-abi-dumper get lookahead token from preprocessor

header-abi-dumper looks ahead one token to determine whether an
identifier is a template. This commit makes the dumper get token from
preprocessor so as to handle template instantiation in macro.

Test: ./test.py
Bug: 117582158
Change-Id: I0e3f3708ec98eba5353fee619f4cfbdc50570a59