Initialize un-initialized variable that breaks wasm tests.

This greens the wasm travis build.

BUG= https://code.google.com/p/v8/issues/detail?id=4203
TEST=asm-wasm tests
TBR=titzer@chromium.org,aseemgarg@chromium.org
LOG=N

Review URL: https://codereview.chromium.org/1490673002

Cr-Commit-Position: refs/heads/master@{#32448}

src/typing-asm.cc

@@ -43,6 +43,7 @@ AsmTyper::AsmTyper(Isolate* isolate, Zone* zone, Script* script,
       root_(root),
       valid_(true),
       allow_simd_(false),
+      property_info_(NULL),
       intish_(0),
       stdlib_types_(zone),
       stdlib_heap_types_(zone),