[WebAssembly] Remove unneeded target operand flags

This change is in preparation for the addition of new target
operand flags for new relocation types.  Have a symbol type as part
of the flag set makes it harder to use and AFAICT these are serving
no purpose.

Differential Revision: https://reviews.llvm.org/D60014

llvm-svn: 357548
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
index 3f5aba0..ee69811 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
@@ -199,7 +199,7 @@
       const char *CPPExnSymbol = MF.createExternalSymbolName("__cpp_exception");
       BuildMI(&MBB, DL, get(WebAssembly::BR_ON_EXN))
           .addMBB(TBB)
-          .addExternalSymbol(CPPExnSymbol, WebAssemblyII::MO_SYMBOL_EVENT)
+          .addExternalSymbol(CPPExnSymbol)
           .add(Cond[1]);
     } else
       BuildMI(&MBB, DL, get(WebAssembly::BR_IF)).addMBB(TBB).add(Cond[1]);