UserspaceEmulator: Mark SimpleRegions as initialized up front for now

This prevents some false positives since the initial stack is expected
to be zero-initialized.

DevTools/UserspaceEmulator/SimpleRegion.cpp

@@ -25,6 +25,7 @@
  */
 
 #include "SimpleRegion.h"
+#include <string.h>
 
 namespace UserspaceEmulator {
 
@@ -32,7 +33,8 @@ SimpleRegion::SimpleRegion(u32 base, u32 size)
     : Region(base, size)
 {
     m_data = (u8*)calloc(1, size);
-    m_shadow_data = (u8*)calloc(1, size);
+    m_shadow_data = (u8*)malloc(size);
+    memset(m_shadow_data, 1, size);
 }
 
 SimpleRegion::~SimpleRegion()