[Scudo] Use GWP-ASan's aligned allocations and fixup postalloc hooks. am: 875cd44ff6 am: 63773cb41b am: ec578a0d9e

Original change: https://android-review.googlesource.com/c/platform/external/gwp_asan/+/1703605

Change-Id: I05cf2bfca592d392475e8cdcd47eaf5cf0f05bf5
diff --git a/gwp_asan/common.h b/gwp_asan/common.h
index ee8f9d1..7ce367e 100644
--- a/gwp_asan/common.h
+++ b/gwp_asan/common.h
@@ -83,6 +83,8 @@
 // crash handler. This, in conjunction with the Metadata array, forms the entire
 // set of information required for understanding a GWP-ASan crash.
 struct AllocatorState {
+  constexpr AllocatorState() {}
+
   // Returns whether the provided pointer is a current sampled allocation that
   // is owned by this pool.
   GWP_ASAN_ALWAYS_INLINE bool pointerIsMine(const void *Ptr) const {