[wasm] Fix location for error in asm.js ToNumber conversion

src/compiler/pipeline.cc

Index: src/compiler/pipeline.cc
diff --git a/src/compiler/pipeline.cc b/src/compiler/pipeline.cc
index f799e51bd1ae3f3c29ec433b9b4de39bcfd7e265..71629373393ed4a16c305c28c988f19f876cd47f 100644
--- a/src/compiler/pipeline.cc
+++ b/src/compiler/pipeline.cc
@@ -137,14 +137,16 @@ class PipelineData {
 
   // For machine graph testing entry point.
   PipelineData(ZoneStats* zone_stats, CompilationInfo* info, Graph* graph,
-               Schedule* schedule)
+               Schedule* schedule, SourcePositionTable* position_table)
       : isolate_(info->isolate()),
         info_(info),
         debug_name_(info_->GetDebugName()),
         zone_stats_(zone_stats),
         graph_zone_scope_(zone_stats_, ZONE_NAME),
         graph_(graph),
-        source_positions_(new (info->zone()) SourcePositionTable(graph_)),
+        source_positions_(position_table ? position_table

[Michael Starzinger, 2016/12/08 11:38:05]

nit: Can we move this piece that maybe allocates a source position table into
the caller? The {Pipeline::GenerateCodeForCodeStub} caller always
unconditionally allocates a source position table. The
{Pipeline::GenerateCodeForTesting} caller would use the conditional allocation.

[Clemens Hammacher, 2016/12/08 12:15:37]

Done. I am wondering though if it would not be better to store a nullptr in the
{PipelineData}, and handle this case whenever source position is looked up.
Allocating the empty source position table and doing a number of lookups on it
might produce some overhead. And GenerateCodeForTesting is not only used for
testing unfortunately.
Maybe we can try to fix this later.

+                                         : new (info->zone())
+                                               SourcePositionTable(graph_)),
         schedule_(schedule),
         instruction_zone_scope_(zone_stats_, ZONE_NAME),
         instruction_zone_(instruction_zone_scope_.zone()),
@@ -1641,7 +1643,7 @@ Handle<Code> Pipeline::GenerateCodeForCodeStub(Isolate* isolate,
 
   // Construct a pipeline for scheduling and code generation.
   ZoneStats zone_stats(isolate->allocator());
-  PipelineData data(&zone_stats, &info, graph, schedule);
+  PipelineData data(&zone_stats, &info, graph, schedule, nullptr);
   std::unique_ptr<PipelineStatistics> pipeline_statistics;
   if (FLAG_turbo_stats || FLAG_turbo_stats_nvp) {
     pipeline_statistics.reset(new PipelineStatistics(&info, &zone_stats));
@@ -1689,13 +1691,12 @@ Handle<Code> Pipeline::GenerateCodeForTesting(CompilationInfo* info,
 }
 
 // static
-Handle<Code> Pipeline::GenerateCodeForTesting(CompilationInfo* info,
-                                              CallDescriptor* call_descriptor,
-                                              Graph* graph,
-                                              Schedule* schedule) {
+Handle<Code> Pipeline::GenerateCodeForTesting(
+    CompilationInfo* info, CallDescriptor* call_descriptor, Graph* graph,
+    Schedule* schedule, SourcePositionTable* source_positions) {
   // Construct a pipeline for scheduling and code generation.
   ZoneStats zone_stats(info->isolate()->allocator());
-  PipelineData data(&zone_stats, info, graph, schedule);
+  PipelineData data(&zone_stats, info, graph, schedule, source_positions);
   std::unique_ptr<PipelineStatistics> pipeline_statistics;
   if (FLAG_turbo_stats || FLAG_turbo_stats_nvp) {
     pipeline_statistics.reset(new PipelineStatistics(info, &zone_stats));