deps: fix missing <cstdint> include in re2 pcre.h

[riosje]

What

Adds the missing #include <cstdint> to deps/grpc/third_party/re2/util/pcre.h, which uses int32_t (line 503) without including the header that defines it.

Why

The file has always relied on transitive header leaks:

• GCC 12 libstdc++ leaks <cstdint> through <string> — removed in GCC 13 (see GCC 13 porting notes).
• glibc keeps leaking the global int32_t via <stdlib.h> → <sys/types.h> → bits/stdint-intn.h, even on GCC 13+.
• musl (Alpine) leaks neither — so the Alpine binary build of Node.js 26 fails with:

deps/grpc/third_party/re2/util/pcre.h:503:11: error: 'int32_t' does not name a type

This blocks the NSolid lithium (Node 26) Alpine build in packages-repositories. Older codenames pass only because their Alpine build images are from 2023 (gcc 12); any image rebuild would break them identically.

Validation

Minimal repro of the same include chain (<string> then bare int32_t), compiled in Docker:

Environment	libc	gcc	before	after
alpine:3.18	musl	12.2.1	pass	pass
alpine:3.20	musl	13.2.1	fail	pass
alpine:3.21	musl	14.2.0	fail	pass
ubuntu:24.04	glibc 2.39	13.3.0	pass	pass

The change is a pure additive standard include — no behavior or ABI change on any toolchain.

Note

Per doc/contributing/pull-requests.md, deps/ changes normally go to their upstream projects. This shim is legacy re2 code vendored by gRPC as a pinned snapshot (bumping the vendored gRPC did not pick up a fix), so this lands directly in our fork to unblock the Node 26 pipeline. Upstream re2 has long since removed/rewritten this compatibility layer.

[ns-control-tower]

Walkthrough

This PR adds #include <cstdint> to deps/grpc/third_party/re2/util/pcre.h (line 163), a vendored gRPC/re2 compatibility header. The file declares mutable int32_t hit_limit_; (class PCRE) without including the standard header that defines int32_t. On glibc/libstdc++ toolchains the type leaks transitively through <string> (GCC ≤12) or <stdlib.h>→<sys/types.h>→bits/stdint-intn.h, so the omission was latent. On musl (Alpine) with GCC 13+ neither leak occurs, causing a hard compile failure that blocks the NSolid lithium (Node 26) Alpine build. The fix is a pure additive standard-library include — no behavior or ABI change on any toolchain.

Assessment

• Correctness ✅ — <cstdint> is the correct C++ header for int32_t, and int32_t hit_limit_ is the only fixed-width integer usage in the file. The include is placed before the project-specific headers (util/util.h, re2/stringpiece.h), consistent with the system-headers-first convention.
• Compatibility ✅ — Additive include; cannot break any existing build (at worst redundant where <cstdint> was already transitively available). The PR description includes a cross-platform validation matrix (Alpine 3.18/3.20/3.21, Ubuntu 24.04) confirming the fix resolves the musl/GCC 13+ failure without regressions.
• Security ✅ — No security implications; a header include fix in a vendored dependency.
• Supply chain ✅ — This is a minimal patch to a vendored, pinned gRPC/re2 snapshot. The PR description correctly notes that deps/ changes normally go upstream, but explains why this shim lands directly in the fork (legacy re2 code, bumping the vendored gRPC did not pick up a fix, upstream re2 has removed/rewritten this compatibility layer). Reasonable for unblocking the Node 26 pipeline.

No blocking findings.

Verdict: APPROVE — clean, minimal, well-justified header fix that resolves a real musl/Alpine build failure with no risk of regression.