docs(vendored): record the Swift scanner shift patch in MANIFEST.md

The vendoring table claims our copy of a grammar matches the pinned
upstream commit. A local patch makes that claim false unless the patch
is written down, so a future re-vendor would drop the fix without
anyone noticing.

The row covers both changed lines, because both are the same defect in
the same file: OP_SYMBOL_SUPPRESSOR at line 131 and eat_operators at
line 514.

MANIFEST.md is itself listed in scripts/vendored-checksums.txt, so its
own recorded checksum moves with the edit.

Refs #1892

Signed-off-by: Joshua Richter <jrichter5781@gmail.com>

Author: CaptainMittens

internal/cbm/vendored/grammars/MANIFEST.md

@@ -71,6 +71,7 @@ Re-vendoring from upstream must re-apply these.
 | rescript   | `rescript/scanner.c`, deserialize | guard `memcpy(state, buffer, n_bytes)` with `if (n_bytes > 0)` | UBSan: zero-length `memcpy` with a NULL `buffer` / `n_bytes == 0` on empty-state deserialize (formal UB, harmless). The sibling serialize copies a fixed `sizeof(ScannerState)` (always > 0, non-NULL src) and needs no guard. |
 | purescript | `purescript/scanner.c`, serialize | guard `memcpy(buffer, indents->data, to_copy)` with `if (to_copy > 0)` | UBSan: zero-length `memcpy` with a NULL/0-size source when the indent vector is empty (formal UB, harmless) |
 | plsql      | `plsql/parser.c`, include         | `#include <tree_sitter/parser.h>` → `#include "tree_sitter/parser.h"` | The older ABI-14 generator emits angle brackets; every other vendored grammar uses the quoted form, which resolves the per-grammar `tree_sitter/` header from the including file's directory |
+| swift      | `swift/scanner.c`, `OP_SYMBOL_SUPPRESSOR` + `eat_operators` | `1UL <<` / `1 <<` → `1ULL <<` | UBSan: `1 << suppressor` shifts an `int` by up to `TOKEN_COUNT` bits, undefined once the index reaches 31, while the mask it feeds is `uint64_t`. `1UL << FAKE_TRY_BANG` is the same defect on Windows, where `unsigned long` is 32 bits and `FAKE_TRY_BANG` is 32; the CLANGARM64 leg runs UBSan in trap mode, so there it is an illegal instruction rather than a log line |
 
 ## Vendored from verified upstream
 

scripts/vendored-checksums.txt

@@ -5,7 +5,7 @@ c5cfb43042b6b72045f4ba997834d0a7786d2793d91680868b5815b39f14fc78  internal/cbm/v
 b29c1c9fb7cc82f58c84b376df1297d6e2737a1d655fd356db0859e3c29c2fea  internal/cbm/vendored/common/tree_sitter/alloc.h
 31e60a1bff6f715afacce03b5b70efe42b58371b4f9595dd4af52a577ff9608c  internal/cbm/vendored/common/tree_sitter/array.h
 180b893c8734778fd32f372dfbc27bd6ad1cd2221f26150b31256ff6716320d2  internal/cbm/vendored/common/tree_sitter/parser.h
-73be629708008f0cb31e0f8d41dc71ae901626baba191c24efd41bf52220c913  internal/cbm/vendored/grammars/MANIFEST.md
+bfb8a2a585024af07bef0f5ddc66400fda3f8aa95caf7f41d0eb55b65d688347  internal/cbm/vendored/grammars/MANIFEST.md
 ad8425038de519f8c4e3e9339feebf99dfad8a6002dcf79227d91402780a32cc  internal/cbm/vendored/grammars/ada/LICENSE
 02805ec13939b749c891567be36bf024b09034e04c80683a1ae667272458d549  internal/cbm/vendored/grammars/ada/parser.c
 115a75d000bef9c70c4de7dfbb7f2a80b90cbb14ba265056dc7abb1ef3b9b6db  internal/cbm/vendored/grammars/ada/tree_sitter/alloc.h