unwind: bump unwinding dependency to 0.2.6

With a recent change to the compiler, all instances of `#[naked]` must
now be wrapped in `#[unsafe(naked)]`. The `unwinding` crate, which is
used on Xous for doing unwinding in constrained environments, needed to
be updated to handle this change.

Bump the `unwinding` dependency to 0.2.6, which performs this wrapping.

Signed-off-by: Sean Cross <sean@xobs.io>

Author: xobs

library/Cargo.lock

@@ -448,9 +448,9 @@ dependencies = [
 
 [[package]]
 name = "unwinding"
-version = "0.2.5"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "51f06a05848f650946acef3bf525fe96612226b61f74ae23ffa4e98bfbb8ab3c"
+checksum = "8393f2782b6060a807337ff353780c1ca15206f9ba2424df18cb6e733bd7b345"
 dependencies = [
  "compiler_builtins",
  "gimli",

library/unwind/Cargo.toml

@@ -22,7 +22,7 @@ cfg-if = "1.0"
 libc = { version = "0.2.140", features = ['rustc-dep-of-std'], default-features = false }
 
 [target.'cfg(target_os = "xous")'.dependencies]
-unwinding = { version = "0.2.5", features = ['rustc-dep-of-std', 'unwinder', 'fde-custom'], default-features = false }
+unwinding = { version = "0.2.6", features = ['rustc-dep-of-std', 'unwinder', 'fde-custom'], default-features = false }
 
 [features]