Update ChangeLog

Author: jiepan-intel

ChangeLog.md

@@ -20,6 +20,9 @@ See docs/process.md for more on how version tagging works.
 
 3.1.74 (in development)
 -----------------------
+- Added support for compiling AVX2 intrinsics, 256-bit wide intrinsic is emulated
+  on top of 128-bit Wasm SIMD instruction set. (#23035). Pass `-msimd128 -mavx2`
+  to enable targeting AVX2.
 - The file system was updated to independently track atime, mtime and ctime
   instead of using the same time for all three. (#22998)
 - The minimum supported chrome version was bumped from 32 to 33. (#23077)