[lld] [llvm] [WebAssembly] Add segment NO_STRIP flag to support private retained data (PR #81539)

[Sam Clegg via llvm-commits]

================
@@ -70,6 +70,8 @@ void MCSectionWasm::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
     OS << 'S';
   if (SegmentFlags & wasm::WASM_SEG_FLAG_TLS)
     OS << 'T';
+  if (SegmentFlags & wasm::WASM_SEG_FLAG_NO_STRIP)
+    OS << 'R';
----------------
sbc100 wrote:

Should we mirror that name and use `WASM_SEG_FLAG_RETAIN` as the name of our flag?

https://github.com/llvm/llvm-project/pull/81539