8296162: [aarch64] Remove unused Address::_is_lval

Reviewed-by: chagedorn, aph

src/hotspot/cpu/aarch64/assembler_aarch64.cpp

@@ -238,7 +238,6 @@ void Assembler::add_sub_immediate(Instruction_aarch64 &current_insn,
 #undef starti
 
 Address::Address(address target, relocInfo::relocType rtype) : _mode(literal){
-  _is_lval = false;
   _target = target;
   switch (rtype) {
   case relocInfo::oop_type:

src/hotspot/cpu/aarch64/assembler_aarch64.hpp

@@ -372,11 +372,6 @@ class Address {
 
   RelocationHolder _rspec;
 
-  // Typically we use AddressLiterals we want to use their rval
-  // However in some situations we want the lval (effect address) of
-  // the item.  We provide a special factory for making those lvals.
-  bool _is_lval;
-
   // If the target is far we'll need to load the ea of this to a
   // register to reach it. Otherwise if near we can do PC-relative
   // addressing.
@@ -405,7 +400,6 @@ class Address {
   Address(address target, RelocationHolder const& rspec)
     : _mode(literal),
       _rspec(rspec),
-      _is_lval(false),
       _target(target)  { }
   Address(address target, relocInfo::relocType rtype = relocInfo::external_word_type);
   Address(Register base, RegisterOrConstant index, extend ext = lsl())