X86: Replace VarHandle.get() return type check with CheckCast node

This commit removes the varType check against the callsite return type.
The check is done after by an added HCheckCast node.

Test: art/test.py --host --32 -r -t 712-varhandle-invocations
Bug: 65872996
Change-Id: If4d966e0087da28349390474188e10dfb6f63832
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 9b984d5..3ad987e 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -4514,7 +4514,6 @@
  public:
   HInvokePolymorphic(ArenaAllocator* allocator,
                      uint32_t number_of_arguments,
-                     uint32_t number_of_other_inputs,
                      DataType::Type return_type,
                      uint32_t dex_pc,
                      uint32_t dex_method_index,
@@ -4525,7 +4524,7 @@
       : HInvoke(kInvokePolymorphic,
                 allocator,
                 number_of_arguments,
-                number_of_other_inputs,
+                /* number_of_other_inputs= */ 0u,
                 return_type,
                 dex_pc,
                 dex_method_index,