Fix compiler warnings & linker errors:

Changes introduced with 1.7.0-b5 and 1.7.0-b6 could result in compiler
warnings and/or linker errors when compiling in certain configurations.

src/ripple/shamap/SHAMapInnerNode.h

@@ -108,6 +108,7 @@ public:
     SHAMapInnerNode(SHAMapInnerNode const&) = delete;
     SHAMapInnerNode&
     operator=(SHAMapInnerNode const&) = delete;
+    ~SHAMapInnerNode();
 
     std::shared_ptr<SHAMapTreeNode>
     clone(std::uint32_t cowid) const override;

src/ripple/shamap/impl/SHAMapInnerNode.cpp

@@ -49,6 +49,8 @@ SHAMapInnerNode::SHAMapInnerNode(
 {
 }
 
+SHAMapInnerNode::~SHAMapInnerNode() = default;
+
 template <class F>
 void
 SHAMapInnerNode::iterChildren(F&& f) const

src/ripple/shamap/impl/TaggedPointer.h

@@ -217,11 +217,6 @@ public:
     getChildIndex(std::uint16_t isBranch, int i) const;
 };
 
-inline TaggedPointer::~TaggedPointer()
-{
-    destroyHashesAndChildren();
-}
-
 }  // namespace ripple
 
 #endif

src/ripple/shamap/impl/TaggedPointer.ipp

@@ -636,4 +636,9 @@ TaggedPointer::getChildren() const
     return result;
 };
 
+inline TaggedPointer::~TaggedPointer()
+{
+    destroyHashesAndChildren();
+}
+
 }  // namespace ripple