protobuf: fix big-endian upb decoding issues (#499461)

pkgs/development/libraries/protobuf/fix-upb-packed-enum-be.patch

@@ -0,0 +1,22 @@
+From 3935d8b9fd740e0ed45fade633ab967baee1dfcc Mon Sep 17 00:00:00 2001
+From: Jonathan Albrecht <jonathan.albrecht@ibm.com>
+Date: Tue, 3 Feb 2026 15:07:37 -0500
+Subject: [PATCH] Fix an endian problem when memcpying in
+ _upb_Decoder_DecodeEnumPacked
+
+---
+ upb/wire/decode.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/upb/wire/decode.c b/upb/wire/decode.c
+index 9b050866b45ea..0810ba3e6116b 100644
+--- a/upb/wire/decode.c
++++ b/upb/wire/decode.c
+@@ -359,6 +359,7 @@ static const char* _upb_Decoder_DecodeEnumPacked(
+       _upb_Decoder_AddEnumValueToUnknown(d, msg, field, &elem);
+       continue;
+     }
++    _upb_Decoder_MungeInt32(&elem);
+     if (_upb_Decoder_Reserve(d, arr, 1)) {
+       out = UPB_PTR_AT(upb_Array_MutableDataPtr(arr),
+                        arr->UPB_PRIVATE(size) * 4, void);

pkgs/development/libraries/protobuf/generic.nix

@@ -65,6 +65,17 @@ stdenv.mkDerivation (finalAttrs: {
         hash = "sha256-2/vc4anc+kH7otfLHfBtW8dRowPyObiXZn0+HtQktak=";
       })
     ]
+    ++ lib.optionals (lib.versionAtLeast version "33") [
+      # Fix protoc plugins crashing on big-endian platforms
+      # https://github.com/protocolbuffers/protobuf/pull/25363
+      (fetchpatch {
+        url = "https://github.com/protocolbuffers/protobuf/commit/8282f0f8ecf8b847e5964a308e041ba3b049811c.patch";
+        hash = "sha256-4c/yLuAd29Cxrz6I9F2Lj02lW2bazIcGb+86uxZY7qA=";
+      })
+      # Fix packed enum decoding on big-endian platforms
+      # https://github.com/protocolbuffers/protobuf/pull/25683
+      ./fix-upb-packed-enum-be.patch
+    ]
     ++ lib.optionals (lib.versionAtLeast version "34") [
       # upb linker-array fix for newer toolchains (notably GCC 15):
       # `UPB_linkarr_internal_empty_upb_AllExts` can conflict with extension