Windows fix: Need to ensure all APIs are forward decl'd with LLDB_API. If not then frontend linker errors appear due to dllexport differences. There may be some others missing, will commit as I find them.

llvm-svn: 206958

lldb/include/lldb/API/SBDefines.h

@@ -65,6 +65,7 @@ class LLDB_API SBStringList;
 class LLDB_API SBSymbol;
 class LLDB_API SBSymbolContext;
 class LLDB_API SBSymbolContextList;
+class LLDB_API SBSection;
 class LLDB_API SBTarget;
 class LLDB_API SBThread;
 class LLDB_API SBType;