add note for miri

LuuuXXX · LuuuXXX · commit f3312609f7a9 · 2025-03-04T20:41:34.000+08:00
diff --git a/src/doc/rustc/src/platform-support/openharmony.md b/src/doc/rustc/src/platform-support/openharmony.md
@@ -29,6 +29,9 @@ The targets require a reasonably up-to-date OpenHarmony SDK on the host.
 
 The targets support `cargo`, which require [ohos-openssl](https://github.com/ohos-rs/ohos-openssl).
 
+`miri` isn't supported yet, since its dependencies (`libffi` and `tikv-jemalloc-sys`) don't support
+compiling for the OHOS targets.
+
 ## Setup
 
 The OpenHarmony SDK doesn't currently support Rust compilation directly, so
