[wasm] Backoff implementation for F64Trunc using std::trunc.

src/assembler.cc

Index: src/assembler.cc
diff --git a/src/assembler.cc b/src/assembler.cc
index 4099e1febcfc5272953c43fc3abaede1f024da80..dd9175c295561b4f9116c76afc27f44381425af2 100644
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -34,6 +34,7 @@
 
 #include "src/assembler.h"
 
+#include <math.h>
 #include <cmath>
 #include "src/api.h"
 #include "src/base/cpu.h"
@@ -1131,6 +1132,12 @@ ExternalReference ExternalReference::compute_output_frames_function(
       Redirect(isolate, FUNCTION_ADDR(Deoptimizer::ComputeOutputFrames)));
 }
 
+static void trunc64_wrapper(double* param) { *param = trunc(*param); }

[ahaas, 2016/02/01 12:04:02]

std::trunc caused problems on android.

+
+ExternalReference ExternalReference::trunc64_wrapper_function(
+    Isolate* isolate) {
+  return ExternalReference(Redirect(isolate, FUNCTION_ADDR(trunc64_wrapper)));
+}
 
 ExternalReference ExternalReference::log_enter_external_function(
     Isolate* isolate) {