[WebAssembly] Don't include lazy symbols in import table

This bug was introduced in: https://reviews.llvm.org/D41304.
Add a test for this case.

Differential Revision: https://reviews.llvm.org/D41309

llvm-svn: 320872
diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp
index 8219754..17f0bc4 100644
--- a/lld/wasm/Writer.cpp
+++ b/lld/wasm/Writer.cpp
@@ -551,7 +551,7 @@
 
 void Writer::calculateImports() {
   for (Symbol *Sym : Symtab->getSymbols()) {
-    if (Sym->isDefined() || Sym->isWeak())
+    if (!Sym->isUndefined() || Sym->isWeak())
       continue;
 
     if (Sym->isFunction()) {