Revert "[WebAssembly] Added default stack-only instruction mode for MC."

This reverts commit 917a99b71ce21c975be7bfbf66f4040f965d9f3c.

llvm-svn: 339630
diff --git a/llvm/test/CodeGen/WebAssembly/signext-arg.ll b/llvm/test/CodeGen/WebAssembly/signext-arg.ll
index 208decc..d32da30 100644
--- a/llvm/test/CodeGen/WebAssembly/signext-arg.ll
+++ b/llvm/test/CodeGen/WebAssembly/signext-arg.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc < %s -asm-verbose=false -wasm-register-codegen-test-mode | FileCheck %s
+; RUN: llc < %s -asm-verbose=false -disable-wasm-explicit-locals | FileCheck %s
 
 target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
 target triple = "wasm32-unknown-unknown"