Update README to reflect AArch64 and x86 support

README.md

@@ -9,7 +9,7 @@ This library serves two purposes:
 1. Provide a pure Rust alternative to libgcc_eh or libunwind.
 2. Provide easier unwinding support for `#![no_std]` targets.
 
-Currently supports x86_64 and RV64.
+Currently supports x86_64, x86, RV64 and AArch64.
 
 ## Unwinder