[WebAssembly] Use the default alignment for SIMD types.

Previously WebAssembly's datalayout string had -v128:8:128. This had been an
attempt to declare a certain level of support for unaligned SIMD accesses.
However, clang makes its own determinations for SIMD alignment that are
independent of the datalayout string, so this wasn't actually meaningful.

llvm-svn: 245494
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index 0f3ac94..25fe846 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -46,8 +46,8 @@
     const TargetOptions &Options, Reloc::Model RM, CodeModel::Model CM,
     CodeGenOpt::Level OL)
     : LLVMTargetMachine(T, TT.isArch64Bit()
-                               ? "e-p:64:64-i64:64-v128:8:128-n32:64-S128"
-                               : "e-p:32:32-i64:64-v128:8:128-n32:64-S128",
+                               ? "e-p:64:64-i64:64-n32:64-S128"
+                               : "e-p:32:32-i64:64-n32:64-S128",
                         TT, CPU, FS, Options, RM, CM, OL),
       TLOF(make_unique<WebAssemblyTargetObjectFile>()) {
   initAsmInfo();