[wasm] Properly plumb the origin of the WASM module from asm.js translation.

src/compiler/wasm-compiler.cc

Index: src/compiler/wasm-compiler.cc
diff --git a/src/compiler/wasm-compiler.cc b/src/compiler/wasm-compiler.cc
index a0f29c85089aaf8ac292facdb736e2bd6e2c213d..16ff311000236d7525095ac09c5ab8c0b4215309 100644
--- a/src/compiler/wasm-compiler.cc
+++ b/src/compiler/wasm-compiler.cc
@@ -1153,6 +1153,13 @@ Node* WasmGraphBuilder::BuildF64Max(Node* left, Node* right) {
 
 Node* WasmGraphBuilder::BuildI32SConvertF32(Node* input) {
   MachineOperatorBuilder* m = jsgraph()->machine();
+  if (module_ && module_->asm_js()) {
+    // asm.js must use the wacky JS semantics.
+    input = graph()->NewNode(m->ChangeFloat32ToFloat64(), input);
+    return graph()->NewNode(
+        m->TruncateFloat64ToInt32(TruncationMode::kJavaScript), input);
+  }
+
   // Truncation of the input value is needed for the overflow check later.
   Node* trunc = Unop(wasm::kExprF32Trunc, input);
   Node* result = graph()->NewNode(m->TruncateFloat32ToInt32(), trunc);
@@ -1169,7 +1176,8 @@ Node* WasmGraphBuilder::BuildI32SConvertF32(Node* input) {
 
 Node* WasmGraphBuilder::BuildI32SConvertF64(Node* input) {
   MachineOperatorBuilder* m = jsgraph()->machine();
-  if (module_ && module_->asm_js) {
+  if (module_ && module_->asm_js()) {
+    // asm.js must use the wacky JS semantics.
     return graph()->NewNode(
         m->TruncateFloat64ToInt32(TruncationMode::kJavaScript), input);
   }
@@ -1189,6 +1197,13 @@ Node* WasmGraphBuilder::BuildI32SConvertF64(Node* input) {
 
 Node* WasmGraphBuilder::BuildI32UConvertF32(Node* input) {
   MachineOperatorBuilder* m = jsgraph()->machine();
+  if (module_ && module_->asm_js()) {
+    // asm.js must use the wacky JS semantics.
+    input = graph()->NewNode(m->ChangeFloat32ToFloat64(), input);
+    return graph()->NewNode(
+        m->TruncateFloat64ToInt32(TruncationMode::kJavaScript), input);
+  }
+
   // Truncation of the input value is needed for the overflow check later.
   Node* trunc = Unop(wasm::kExprF32Trunc, input);
   Node* result = graph()->NewNode(m->TruncateFloat32ToUint32(), trunc);
@@ -1205,7 +1220,8 @@ Node* WasmGraphBuilder::BuildI32UConvertF32(Node* input) {
 
 Node* WasmGraphBuilder::BuildI32UConvertF64(Node* input) {
   MachineOperatorBuilder* m = jsgraph()->machine();
-  if (module_ && module_->asm_js) {
+  if (module_ && module_->asm_js()) {
+    // asm.js must use the wacky JS semantics.
     return graph()->NewNode(
         m->TruncateFloat64ToInt32(TruncationMode::kJavaScript), input);
   }
@@ -1889,7 +1905,7 @@ Node* WasmGraphBuilder::LoadMem(wasm::LocalType type, MachineType memtype,
                                 Node* index, uint32_t offset) {
   Node* load;
 
-  if (module_ && module_->asm_js) {
+  if (module_ && module_->asm_js()) {
     // asm.js semantics use CheckedLoad (i.e. OOB reads return 0ish).
     DCHECK_EQ(0, offset);
     const Operator* op = jsgraph()->machine()->CheckedLoad(memtype);
@@ -1924,7 +1940,7 @@ Node* WasmGraphBuilder::LoadMem(wasm::LocalType type, MachineType memtype,
 Node* WasmGraphBuilder::StoreMem(MachineType memtype, Node* index,
                                  uint32_t offset, Node* val) {
   Node* store;
-  if (module_ && module_->asm_js) {
+  if (module_ && module_->asm_js()) {
     // asm.js semantics use CheckedStore (i.e. ignore OOB writes).
     DCHECK_EQ(0, offset);
     const Operator* op =