Remove includes in .cpp files for things the corresponding .h file already included

src/coins.cpp

@@ -5,11 +5,8 @@
 #include <coins.h>
 
 #include <consensus/consensus.h>
-#include <memusage.h>
 #include <random.h>
 
-#include <assert.h>
-
 bool CCoinsView::GetCoin(const COutPoint &outpoint, Coin &coin) const { return false; }
 uint256 CCoinsView::GetBestBlock() const { return uint256(); }
 std::vector<uint256> CCoinsView::GetHeadBlocks() const { return std::vector<uint256>(); }