[WebAssembly] Fix build failures introduced in r305769

This fixes two build failures that only occur in certain
configurations:
- error: unused function 'operator<<'
- error: control reaches end of non-void function

Differential Revision: https://reviews.llvm.org/D34382

llvm-svn: 305770
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index a4faaf0..dd2e371 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -162,8 +162,7 @@
 #endif
 };
 
-inline raw_ostream &operator<<(raw_ostream &OS,
-                               const WasmRelocationEntry &Rel) {
+raw_ostream &operator<<(raw_ostream &OS, const WasmRelocationEntry &Rel) {
   Rel.print(OS);
   return OS;
 }