[wasm] Provide better stack traces for asm.js code

src/asmjs/asm-wasm-builder.cc

Index: src/asmjs/asm-wasm-builder.cc
diff --git a/src/asmjs/asm-wasm-builder.cc b/src/asmjs/asm-wasm-builder.cc
index 1cb67edd6e0dbc28c14f5277e4b89d0afcf4f2cb..10c5fc7e56e3a7c8b81d5caa7fdca853e77c6e14 100644
--- a/src/asmjs/asm-wasm-builder.cc
+++ b/src/asmjs/asm-wasm-builder.cc
@@ -1359,11 +1359,13 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
           uint32_t index = imported_function_table_.LookupOrInsertImport(
               vp->var(), sig.Build());
           VisitCallArgs(expr);
+          current_function_builder_->AddAsmWasmOffset(expr->position());
           current_function_builder_->Emit(kExprCallFunction);
           current_function_builder_->EmitVarInt(index);
         } else {
           WasmFunctionBuilder* function = LookupOrInsertFunction(vp->var());
           VisitCallArgs(expr);
+          current_function_builder_->AddAsmWasmOffset(expr->position());
           current_function_builder_->Emit(kExprCallFunction);
           current_function_builder_->EmitDirectCallIndex(
               function->func_index());
@@ -1389,6 +1391,7 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
         VisitCallArgs(expr);
 
         current_function_builder_->EmitGetLocal(tmp.index());
+        current_function_builder_->AddAsmWasmOffset(expr->position());
         current_function_builder_->Emit(kExprCallIndirect);
         current_function_builder_->EmitVarInt(indices->signature_index);
         returns_value =