Partial nonce-code -- should be silent without IRDB relocs added.  Also refactored byte_map into memory_space.

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Instead of adding a new segment to point to strata,
put the .strata section in the 1th segment. This
will prevent the additional segment header from
overwriting part of the text segment when the
.text segment starts very early in the file.

1. Add the ability to rewrite section headers.
We need this because extending sections requires
that their headers be rewritten or the contents
that are in the extended ranges get zero-d.

2. Internally "segmentize" the .strata section
We no longer need to call out to add a segment
for .strata.

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cgc_allocate returns 0 on success

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Also, give user an option to override the
detected architecture.

This commit prevents fallthroughpinned optimization
from running on an instruction that is a jump
or that has a callback associated with it.

It also fixes some errors that cause problems with older
versions of gcc.