[lldb][NFCI] Remove MappedHash.h

This is no longer used as of 8e71d14.

Differential Revision: https://reviews.llvm.org/D157455

Author: bulbazord

lldb/include/lldb/Core/MappedHash.h

@@ -10,7 +10,6 @@
 #include "ObjCLanguageRuntime.h"
 
 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
-#include "lldb/Core/MappedHash.h"
 #include "lldb/Core/Module.h"
 #include "lldb/Core/PluginManager.h"
 #include "lldb/Core/ValueObject.h"