1. decl_for searched the DESTINATION for the SEED's name: a RENAMED symbol's
destination spelling can only exist under the MEMBER's name, so the
destination preference silently never applied to renamed data symbols
(D_801B9DF8 adopted the seed's 'short' against the TU's file-scope 's32').
dest/fleet tiers now search target_sym; seed tiers keep the seed name.
2. dest_scope is FILE-SCOPE-ONLY (brace-masked): the TUs are full of
block-scope externs inside banked bodies, and a flat regex adopted one of
those as 'the destination spelling' over the DEFINE macro's true file-scope
decl.
3. A body-embedded block extern that diverges from the destination file scope
is rewritten to the destination spelling when every use is ADDRESS-ONLY
(type is codegen-irrelevant for &sym); valued uses keep the seed spelling.
+ fix_tu_ret_decls.draft_ret now parses K&R definitions (its first run SKIPped
30 of 32 because the param decls sit between ')' and '{').
Drew T