fix: Patch coarsetime for MIPS AtomicU64 support

- Vendor coarsetime crate with portable-atomic fallback
- Use portable-atomic on targets without 64-bit atomics
- Patch crates.io to use local coarsetime
- Fixes MIPS build failure (AtomicU64 missing)

third_party/coarsetime/Cargo.toml.orig

@@ -0,0 +1,47 @@
+[package]
+name = "coarsetime"
+version = "0.1.37"
+description = "Time and duration crate optimized for speed"
+authors = ["Frank Denis <github@pureftpd.org>"]
+keywords = ["time", "date", "duration"]
+readme = "README.md"
+license = "BSD-2-Clause"
+homepage = "https://github.com/jedisct1/rust-coarsetime"
+repository = "https://github.com/jedisct1/rust-coarsetime"
+categories = ["concurrency", "date-and-time", "os"]
+edition = "2018"
+
+[features]
+wasi-abi2 = ["dep:wasi-abi2"]
+
+[target.'cfg(not(any(target_os = "wasix", target_os = "wasi")))'.dependencies]
+libc = "0.2"
+
+[target.'cfg(target_os = "wasi")'.dependencies]
+wasi-abi2 = { package = "wasi", version = "0.14.7", optional = true }
+
+[target.'cfg(any(target_os = "wasix", target_os = "wasi"))'.dependencies]
+wasix = "0.13"
+
+[target.'cfg(all(any(target_arch = "wasm32", target_arch = "wasm64"), target_os = "unknown"))'.dependencies]
+wasm-bindgen = "0.2"
+
+[dev-dependencies]
+benchmark-simple = "0.1.10"
+
+[profile.bench]
+codegen-units = 1
+
+[[bench]]
+name = "benchmark"
+harness = false
+
+[profile.release]
+lto = true
+panic = "abort"
+opt-level = 3
+codegen-units = 1
+incremental = false
+
+[profile.dev]
+overflow-checks=true