Address review feedback: use emitDispCommentForHandle and remove test

Use emitDispCommentForHandle instead of directly calling eeGetMethodFullName
and printf, matching the pattern used by movz/movk constant annotations.

Remove the FileCheck test since it would only run in checked mode where
the method name already appears on the movz/movk constant instructions.

Co-authored-by: EgorBo <523221+EgorBo@users.noreply.github.com>
Agent-Logs-Url: https://github.com/dotnet/runtime/sessions/84a22a2e-9c3e-40ef-ab3b-97113c002f92

Author: Copilot

src/coreclr/jit/emitarm64.cpp

@@ -13560,11 +13560,7 @@ void emitter::emitDispInsHelp(
                 emitDispReg(id->idReg3(), EA_PTRSIZE, false);
             }
 
-            if (id->idDebugOnlyInfo()->idMemCookie != 0)
-            {
-                methodName = m_compiler->eeGetMethodFullName((CORINFO_METHOD_HANDLE)id->idDebugOnlyInfo()->idMemCookie);
-                printf("      // %s", methodName);
-            }
+            emitDispCommentForHandle(0, id->idDebugOnlyInfo()->idMemCookie, GTF_ICON_FTN_ADDR);
             break;
 
         case IF_LS_1A: // LS_1A   XX...V..iiiiiiii iiiiiiiiiiittttt      Rt    PC imm(1MB)