GP-3276 Put all C++ classes in ghidra namespace

Ghidra/Features/Decompiler/src/decompile/cpp/opbehavior.cc

@@ -16,6 +16,8 @@
 #include "opbehavior.hh"
 #include "translate.hh"
 
+namespace ghidra {
+
 /// This routine generates a vector of OpBehavior objects indexed by opcode
 /// \param inst is the vector of behaviors to be filled
 /// \param trans is the translator object needed by the floating point behaviors
@@ -763,3 +765,5 @@ uintb OpBehaviorLzcount::evaluateUnary(int4 sizeout,int4 sizein,uintb in1) const
 {
   return (uintb)(count_leading_zeros(in1) - 8*(sizeof(uintb) - sizein));
 }
+
+} // End namespace ghidra