Deprecate changeRegisterKind

This API as indicated by the comment is lightly tested. In fact the
code generator should now have the ability to change the register kind
as this is a highly complex topic only the register allocator
understands. Deprecating this API to avoid shooting ourselves in the
foot by mistakenly using this API without understanding what it does.

Signed-off-by: Filip Jeremic <fjeremic@ca.ibm.com>

compiler/z/codegen/OMRCodeGenerator.cpp

@@ -1193,17 +1193,6 @@ OMR::Z::CodeGenerator::canUseImmedInstruction( int64_t value )
       return false;
    }
 
-
-// Use with care, lightly tested
-// Z
-void OMR::Z::CodeGenerator::changeRegisterKind(TR::Register * temp, TR_RegisterKinds rk)
-   {
-   if (rk == temp->getKind()) return;
-   if (_liveRegisters[temp->getKind()] && _liveRegisters[rk])
-      TR_LiveRegisters::moveRegToList(_liveRegisters[temp->getKind()], _liveRegisters[rk], temp);
-   temp->setKind(rk);
-   }
-
 bool
 OMR::Z::CodeGenerator::isAddMemoryUpdate(TR::Node * node, TR::Node * valueChild)
    {

compiler/z/codegen/OMRCodeGenerator.hpp

@@ -225,8 +225,6 @@ class OMR_EXTENSIBLE CodeGenerator : public OMR::CodeGenerator
    bool shouldValueBeInACommonedNode(int64_t value);
    int64_t getLargestNegConstThatMustBeMaterialized() {return ((-1ll) << 31) - 1;}   // min 32bit signed integer minus 1
    int64_t getSmallestPosConstThatMustBeMaterialized() {return ((int64_t)0x000000007FFFFFFF) + 1;}   // max 32bit signed integer plus 1
-
-   void changeRegisterKind(TR::Register * temp, TR_RegisterKinds rk);
 
    void beginInstructionSelection();
    void endInstructionSelection();