[asmjs] Flush after printing error message

This hopefully avoids multiple error messages appearing on the same
line.

R=titzer@chromium.org, machenbach@chromium.org
BUG=chromium:660016

Review-Url: https://codereview.chromium.org/2503423006
Cr-Commit-Position: refs/heads/master@{#41070}

src/asmjs/asm-js.cc

@@ -158,6 +158,7 @@ MaybeHandle<FixedArray> AsmJs::ConvertAsmToWasm(ParseInfo* info) {
   if (!typer.Validate()) {
     DCHECK(!info->isolate()->has_pending_exception());
     PrintF("Validation of asm.js module failed: %s", typer.error_message());
+    Flush();
     return MaybeHandle<FixedArray>();
   }
   v8::internal::wasm::AsmWasmBuilder builder(info->isolate(), info->zone(),