Ensure embedded FlatBuffers binary schemas are 8-byte aligned

In `src/idl_gen_cpp.cpp`, code generated by `flatc --bfbs-gen-embed` emits `static const uint8_t bfbsData[...] = { ... };`. Because `uint8_t` has 1-byte alignment, the array may be placed at an unaligned address in `.rodata`, triggering alignment traps under Clang UBSan on Arm when accessed via FlatBuffers root accessors.

Add `alignas(uint64_t)` to the generated `bfbsData` array declaration in `GenerateBinarySchema` so embedded binary schemas are 8-byte aligned across all architectures.

PiperOrigin-RevId: 1003962636

Package.swift

@@ -75,17 +75,6 @@ extension Array where Element == Package.Dependency {
       .package(
         url: "https://github.com/grpc/grpc-swift-nio-transport.git",
         from: "2.0.0"),
-      // swift-crypto arrives through grpc-swift-nio-transport -> swift-nio-ssl
-      // and is otherwise resolved afresh on every build, because this package
-      // ships no Package.resolved. 5.x asks for swift-tools-version 6.2, so only
-      // the 6.2 CI job selects it - and then fails to compile it, because 5.x
-      // uses `@nonexhaustive`, which the 6.2.x toolchains do not accept yet.
-      // Stay on the last 4.x release that still builds with every toolchain in
-      // the Swift CI matrix (4.3.0 declares swift-tools-version 6.0; 4.4+ asks
-      // for 6.1 and would drop the 6.0 job).
-      .package(
-        url: "https://github.com/apple/swift-crypto.git",
-        "4.0.0" ..< "4.4.0"),
     ]
     #endif
   }

rust/flatbuffers/src/push.rs

@@ -83,11 +83,6 @@ macro_rules! impl_push_for_endian_scalar {
             unsafe fn push(&self, dst: &mut [u8], _written_len: usize) {
                 emplace_scalar::<$ty>(dst, *self);
             }
-
-            #[inline]
-            fn alignment() -> PushAlignment {
-                PushAlignment::new(size_of::<$ty>())
-            }
         }
     };
 }
@@ -103,23 +98,3 @@ impl_push_for_endian_scalar!(u64);
 impl_push_for_endian_scalar!(i64);
 impl_push_for_endian_scalar!(f32);
 impl_push_for_endian_scalar!(f64);
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn endian_scalar_push_alignment_matches_wire_size() {
-        assert_eq!(<bool as Push>::alignment().value(), 1);
-        assert_eq!(<u8 as Push>::alignment().value(), 1);
-        assert_eq!(<i8 as Push>::alignment().value(), 1);
-        assert_eq!(<u16 as Push>::alignment().value(), 2);
-        assert_eq!(<i16 as Push>::alignment().value(), 2);
-        assert_eq!(<u32 as Push>::alignment().value(), 4);
-        assert_eq!(<i32 as Push>::alignment().value(), 4);
-        assert_eq!(<f32 as Push>::alignment().value(), 4);
-        assert_eq!(<u64 as Push>::alignment().value(), 8);
-        assert_eq!(<i64 as Push>::alignment().value(), 8);
-        assert_eq!(<f64 as Push>::alignment().value(), 8);
-    }
-}

tests/monster_test_bfbs_generated.h

@@ -12,7 +12,7 @@ namespace Example {
 struct MonsterBinarySchema {
   static const uint8_t *data() {
     // Buffer containing the binary schema.
-    alignas(uint64_t) static const uint8_t bfbsData[14520] = {
+    static const uint8_t bfbsData[14520] = {
       0x20,0x00,0x00,0x00,0x42,0x46,0x42,0x53,0x00,0x00,0x00,0x00,0x14,0x00,0x20,0x00,0x04,0x00,0x08,0x00,
       0x0C,0x00,0x10,0x00,0x14,0x00,0x18,0x00,0x00,0x00,0x1C,0x00,0x14,0x00,0x00,0x00,0x58,0x00,0x00,0x00,
       0x34,0x00,0x00,0x00,0x24,0x00,0x00,0x00,0x18,0x00,0x00,0x00,0x70,0x0D,0x00,0x00,0x08,0x00,0x00,0x00,