Update release notes for Wasm improvements to nm and objdump (#81924)

Describes improvements made for #76107

Author: dschuff

llvm/docs/ReleaseNotes.rst

@@ -136,6 +136,12 @@ Changes to the Debug Info
 
 Changes to the LLVM tools
 ---------------------------------
+* llvm-nm and llvm-objdump can now print symbol information from linked
+  WebAssembly binaries, using information from exports or the "name"
+  section for functions, globals and data segments. Symbol addresses and sizes
+  are printed as offsets in the file, allowing for binary size analysis. Wasm
+  files using reference types and GC are also supported (but also only for
+  functions, globals, and data, and only for listing symbols and names).
 
 Changes to LLDB
 ---------------------------------