Convert float64 to float32 when coerced with a heapf32 assignment.

test/cctest/test-asm-validator.cc

Index: test/cctest/test-asm-validator.cc
diff --git a/test/cctest/test-asm-validator.cc b/test/cctest/test-asm-validator.cc
index 2eaaa55ed17109afe46d72f68eef21f3d7d28ea0..967d0b10f3b1a156b1cf6e5324d62df3d7fc5772 100644
--- a/test/cctest/test-asm-validator.cc
+++ b/test/cctest/test-asm-validator.cc
@@ -2348,3 +2348,21 @@ TEST(Imports) {
   }
   CHECK_TYPES_END
 }
+
+TEST(StoreFloatFromDouble) {
+  CHECK_FUNC_TYPES_BEGIN(
+      "function bar() { f32[0] = 0.0; }\n"
+      "function foo() { bar(); }") {
+    CHECK_EXPR(FunctionLiteral, FUNC_V_TYPE) {
+      CHECK_EXPR(Assignment, Bounds(cache.kAsmDouble)) {
+        CHECK_EXPR(Property, Bounds::Unbounded()) {
+          CHECK_VAR(f32, Bounds(cache.kFloat32Array));
+          CHECK_EXPR(Literal, Bounds(cache.kAsmFixnum));
+        }
+        CHECK_EXPR(Literal, Bounds(cache.kAsmDouble));
+      }
+    }
+    CHECK_SKIP();
+  }
+  CHECK_FUNC_TYPES_END
+}