[WebAssembly] Add missing _S opcodes of atomic stores to InstPrinter

[aheejin]

Summary

This was missing in D48839 (rL336145).

[aardappel]

Ah yes, I added these too in my WiP.

lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.h

inline unsigned GetDefaultP2Align(unsigned Opcode) {
   case WebAssembly::ATOMIC_LOAD8_U_I32_S:
   case WebAssembly::ATOMIC_LOAD8_U_I64:
   case WebAssembly::ATOMIC_LOAD8_U_I64_S:
   case WebAssembly::STORE8_I32:
   case WebAssembly::STORE8_I32_S:
   case WebAssembly::STORE8_I64:
   case WebAssembly::STORE8_I64_S:
   case WebAssembly::ATOMIC_STORE8_I32:
+  case WebAssembly::ATOMIC_STORE8_I32_S:
   case WebAssembly::ATOMIC_STORE8_I64:
+  case WebAssembly::ATOMIC_STORE8_I64_S:
     return 0;
   case WebAssembly::LOAD16_S_I32:
   case WebAssembly::LOAD16_S_I32_S:
   case WebAssembly::LOAD16_U_I32:
   case WebAssembly::LOAD16_U_I32_S:
   case WebAssembly::LOAD16_S_I64:
   case WebAssembly::LOAD16_S_I64_S:
   case WebAssembly::LOAD16_U_I64:
   case WebAssembly::LOAD16_U_I64_S:
   case WebAssembly::ATOMIC_LOAD16_U_I32:
   case WebAssembly::ATOMIC_LOAD16_U_I32_S:
   case WebAssembly::ATOMIC_LOAD16_U_I64:
   case WebAssembly::ATOMIC_LOAD16_U_I64_S:
   case WebAssembly::STORE16_I32:
   case WebAssembly::STORE16_I32_S:
   case WebAssembly::STORE16_I64:
   case WebAssembly::STORE16_I64_S:
   case WebAssembly::ATOMIC_STORE16_I32:
+  case WebAssembly::ATOMIC_STORE16_I32_S:
   case WebAssembly::ATOMIC_STORE16_I64:
+  case WebAssembly::ATOMIC_STORE16_I64_S:
     return 1;
   case WebAssembly::LOAD_I32:
   case WebAssembly::LOAD_I32_S:
   case WebAssembly::LOAD_F32:
   case WebAssembly::LOAD_F32_S:
   case WebAssembly::STORE_I32:
   case WebAssembly::STORE_I32_S:
   case WebAssembly::STORE_F32:
   case WebAssembly::STORE_F32_S:
   case WebAssembly::LOAD32_S_I64:
   case WebAssembly::LOAD32_S_I64_S:
   case WebAssembly::LOAD32_U_I64:
   case WebAssembly::LOAD32_U_I64_S:
   case WebAssembly::STORE32_I64:
   case WebAssembly::STORE32_I64_S:
   case WebAssembly::ATOMIC_LOAD_I32:
   case WebAssembly::ATOMIC_LOAD_I32_S:
   case WebAssembly::ATOMIC_LOAD32_U_I64:
   case WebAssembly::ATOMIC_LOAD32_U_I64_S:
   case WebAssembly::ATOMIC_STORE_I32:
+  case WebAssembly::ATOMIC_STORE_I32_S:
   case WebAssembly::ATOMIC_STORE32_I64:
+  case WebAssembly::ATOMIC_STORE32_I64_S:
     return 2;
   case WebAssembly::LOAD_I64:
   case WebAssembly::LOAD_I64_S:
   case WebAssembly::LOAD_F64:
   case WebAssembly::LOAD_F64_S:
   case WebAssembly::STORE_I64:
   case WebAssembly::STORE_I64_S:
   case WebAssembly::STORE_F64:
   case WebAssembly::STORE_F64_S:
   case WebAssembly::ATOMIC_LOAD_I64:
   case WebAssembly::ATOMIC_LOAD_I64_S:
   case WebAssembly::ATOMIC_STORE_I64:
+  case WebAssembly::ATOMIC_STORE_I64_S:
     return 3;
   default:
     llvm_unreachable("Only loads and stores have p2align values");
   }
 }
 
 /// The operand number of the load or store address in load/store instructions.
 static const unsigned LoadAddressOperandNo = 3;