Fix wasm32v1-none compilation errors

- arrayvec.rs: Use concrete return types ([T], slice::Iter, slice::IterMut)
  instead of Self::Target/Self::IntoIter to avoid E0223 ambiguity
  introduced by the Receiver trait in Rust 1.87+
- char.rs: Explicitly import Result/Ok/Err from core for target_os=none
  where the standard prelude is not auto-injected

Cargo.toml

@@ -0,0 +1,111 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+rust-version = "1.51"
+name = "arrayvec"
+version = "0.7.6"
+authors = ["bluss"]
+build = false
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+description = "A vector with fixed capacity, backed by an array (it can be stored on the stack too). Implements fixed capacity ArrayVec and ArrayString."
+documentation = "https://docs.rs/arrayvec/"
+readme = "README.md"
+keywords = [
+    "stack",
+    "vector",
+    "array",
+    "data-structure",
+    "no_std",
+]
+categories = [
+    "data-structures",
+    "no-std",
+]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/bluss/arrayvec"
+
+[package.metadata.docs.rs]
+features = [
+    "borsh",
+    "serde",
+    "zeroize",
+]
+
+[package.metadata.release]
+no-dev-version = true
+tag-name = "{{version}}"
+
+[profile.bench]
+debug = 2
+
+[profile.release]
+debug = 2
+
+[lib]
+name = "arrayvec"
+path = "src/lib.rs"
+
+[[test]]
+name = "borsh"
+path = "tests/borsh.rs"
+
+[[test]]
+name = "serde"
+path = "tests/serde.rs"
+
+[[test]]
+name = "tests"
+path = "tests/tests.rs"
+
+[[bench]]
+name = "arraystring"
+path = "benches/arraystring.rs"
+harness = false
+
+[[bench]]
+name = "extend"
+path = "benches/extend.rs"
+harness = false
+
+[dependencies.borsh]
+version = "1.2.0"
+optional = true
+default-features = false
+
+[dependencies.serde]
+version = "1.0"
+optional = true
+default-features = false
+
+[dependencies.zeroize]
+version = "1.4"
+optional = true
+default-features = false
+
+[dev-dependencies.bencher]
+version = "0.1.4"
+
+[dev-dependencies.matches]
+version = "0.1"
+
+[dev-dependencies.serde_test]
+version = "1.0"
+
+[build-dependencies]
+
+[features]
+default = ["std"]
+std = []