Unify instruction namings also dirs

Was getting confused myself, where it was instruction or instructions, when if the base class was inside or out of dir.
Now dirs are plural, and base class is inside.

lib/slot_machine/instructions/dynamic_call.rb

@@ -0,0 +1,50 @@
+module SlotMachine
+
+  # A dynamic call calls a method at runtime. This off course implies that we don't know the
+  # method at compile time and so must "find" it. Resolving, or finding the method, is a
+  # a seperate instruction though, and here we assume that we know this Method instance.
+  #
+  # Both (to be called) Method instance and the type of receiver are stored as
+  # variables here. The type is used to check before calling.
+  #
+  # Setting up the method is not part of this instructions scope. That setup
+  # includes the type check and any necccessay method resolution.
+  # See sol send statement
+  #
+  class DynamicCall < Instruction
+    attr :cache_entry
+
+    def initialize(type = nil, method = nil)
+      @cache_entry = Parfait::CacheEntry.new(type, method)
+    end
+
+    def to_s
+      str = "DynamicCall "
+      str += cache_entry.cached_method&.name if cache_entry
+      str
+    end
+
+    # One could almost think that one can resolve this to a Risc::FunctionCall
+    #  (which btw resolves to a simple jump), alas, the FunctionCall, like all other
+    # jumping, resolves the address at compile time.
+    #
+    # Instead we need a DynamicJump instruction that explicitly takes a register as
+    # a target (not a label)
+    def to_risc(compiler)
+      entry = @cache_entry
+      compiler.add_constant( entry )
+      return_label = Risc.label(self, "continue_#{object_id}")
+      compiler.build("DynamicCall") do
+        return_address! << return_label
+        next_message! << message[:next_message]
+        next_message[:return_address] << return_address
+        message << message[:next_message]
+        cache_entry! << entry
+        cache_entry << cache_entry[:cached_method]
+        add_code Risc::DynamicJump.new("DynamicCall", cache_entry )
+        add_code return_label
+      end
+    end
+  end
+
+end