advisory: fpc-bootstrap canary red at 603cf2bd — forwards drift + enum-arg from b310

• Type: advisory regression (FPC-seed canary, NOT self-host — self-host fixedpoint stayed byte-identical throughout; only "FPC still accepts the source" broke).
• Found: borg tstate STILL-RED, bisect bad 603cf2bda859 last good 9ae7a3617ccb.
• Resolved: e4e68e88, 2026-07-14.

Root cause (4 errors, 2 kinds)

FPC compiles single-pass and strict; pxx prescans headers and is lax on enum<->int. Drift accumulates silently until the canary runs:

1. Missing forwards (use-before-body in linear include text):
   • EnableExceptionRuntime (parser.inc:7875 use, body :21763) → forwards.inc
   • IsASTLValue (ir.inc:798 use, body :1420) → forwards.inc
   • IREmitNodeRISCV32 forward sat BELOW its first two call sites in ir_codegen_riscv32.inc → moved above EmitAnsiStringFromNodeRISCV32
2. cparser.inc (b310 anonymous bit-fields): TypeSize(IntToTypeKind(fTk)) fed a TTypeKind to the int→enum converter; TypeSize takes TTypeKind directly. Semantically identical under pxx, type error under FPC.

Gate

FPC 103941 lines compiled clean; --tier quick green; self-host fixedpoint byte-identical; fpc-bootstrap#00 PASS locally.

Note

The bisect blamed only 603cf2bd, but 3 of 4 errors predate it (FPC stops at first module failure, so older drift hid behind whichever error came first).