binfmt-detector-cli: rewrite to support PE32+ binaries (#38)

Rewrite with hard-coded offsets into the PE file format to discern
if a binary is PE32 or PE32+, and then to determine if it contains
a "CLR Data Directory" entry that looks valid.

Tested with PE32 and PE32+ compiled Mono binaries, PE32 and PE32+ native
binaries, and a random assortment of garbage files.

Former-commit-id: 9e7ac86ec84f653a2f79b87183efd5b0ebda001b

mcs/class/I18N/CJK/big5.table.REMOVED.git-id

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-e254df03b629552cdfc0bd7fc7fdd3f08a276d55

mcs/class/I18N/CJK/gb2312.table.REMOVED.git-id

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-9e3f99b83deac10f5d0a39ca56c6fc59b6433e36

mcs/class/I18N/CJK/ks.table.REMOVED.git-id

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-6edd81a9270e1662d364ff5b4cc71243fdf61e2a