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i386: multidim SetLength mints an untyped temporary

Repro

program md;
var m: array of array of Integer;
begin
  SetLength(m, 3, 5);
  Writeln('ok ', Length(m), ' ', Length(m[2]));
end.



$ ./compiler/pascal26 --target=i386 md.pas md
pascal26:6: error: target i386: a compiler-minted temporary reached codegen
with an UNRESOLVED type (tyUnknown) — the type inference, not the backend, is
the gap

Pre-existing, not a regression: stable_linux_amd64/default/pinned fails the same way. Native / arm32 / aarch64 / riscv32 all build and print ok 3 5.

Root cause — a synthesiser that skipped the house convention

SetLength(m, d0, d1) desugars in BuildMultiSetLen into the outer call plus for i := 0 to d0-1 do SetLength(m[i], d1). That d0-1 is a hand-built AN_BINOP, and its ASTTk was never stamped.

The IR lowering copies ASTTk[node] into the IR node verbatim — it does not infer a binop's type from its operands (compiler/ir.inc, the AN_BINOP tail: IRAppend(IR_BINOP, left, right, ASTIVal[node], 0, ASTTk[node])). So the limit lowered with IRTk = 0, and the AN_FOR lowering then did

forLimTmp := AllocVar('', IntToTypeKind(IRTk[limitValNode]));

minting a tyUnknown symbol. x86-64's fat 8-byte slot swallows that; i386's IREmit386CheckScalarSym correctly refuses it, and its message is exactly right — the gap is in type inference, not in the backend.

Every other synthesiser in the file already stamps the type (BuildFlatNDIndex / BuildPartialNDRowIndex in pasparser_call.inc set ASTTk := Ord(tyInteger) on all five binops they mint). These two were the omission — and, as usual, it was a double case: BuildMultiSetLen and BuildSetLenNest carry the identical bug, and both had to be fixed.

Fix

ASTTk[limitN] := Ord(tyInteger) in both. Verified ok 3 5 on native, i386, arm32, aarch64 and riscv32.

Note for later

The AN_FOR lowering deliberately keeps no fallback for a tyUnknown limit. A guard there would have silently papered over this and over the next omission of the same shape; i386's refusal is the diagnostic that found it in one step.

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