[Compiler] Skip Ignition for asm.js code.

Since we can't OSR from an function compiled with Ignition, this makes it
impossible to tier up asm.js code as it is running. As such, this CL
bypasses Ignition for asm.js code.

BUG=v8:4280
LOG=N

Review-Url: https://codereview.chromium.org/1994223002
Cr-Commit-Position: refs/heads/master@{#36483}

src/compiler.cc

@@ -434,6 +434,11 @@ bool UseIgnition(CompilationInfo* info) {
     return false;
   }
 
+  // Since we can't OSR from Ignition, skip Ignition for asm.js functions.
+  if (info->shared_info()->asm_function()) {
+    return false;
+  }
+
   // Checks whether top level functions should be passed by the filter.
   if (info->shared_info()->is_toplevel()) {
     Vector<const char> filter = CStrVector(FLAG_ignition_filter);