Update Complex to match methods spec

Author: bjfish

spec/tags/truffle/methods_tags.txt

@@ -1,9 +1,6 @@
 fails:Public methods on Array should include all?
 fails:Public methods on Array should include none?
 fails:Public methods on Array should include one?
-fails:Public methods on Complex should include to_c
-fails:Public methods on Complex should not include divide
-fails:Public methods on Complex should not include marshal_load
 fails:Public methods on File should include birthtime
 fails:Public methods on File should not include inspect
 fails:Public methods on File should not include stat

src/main/ruby/truffleruby/core/complex.rb

@@ -159,7 +159,7 @@ def *(other)
     end
   end
 
-  def divide(other)
+  def /(other)
     if other.kind_of?(Complex)
       self * other.conjugate / other.abs2
     elsif other.kind_of?(Numeric) && other.real?
@@ -168,8 +168,7 @@ def divide(other)
       redo_coerced(:quo, other)
     end
   end
-  alias_method :/, :divide
-  alias_method :quo, :divide
+  alias_method :quo, :/
 
   def ** (other)
     if !other.kind_of?(Float) && other == 0
@@ -290,6 +289,10 @@ def rect
   end
   alias_method :rectangular, :rect
 
+  def to_c
+    self
+  end
+
   def to_f
     raise RangeError, "can't convert #{self} into Float" unless !imag.kind_of?(Float) && imag == 0
     real.to_f
@@ -372,6 +375,7 @@ def marshal_load(ary)
     end
     self
   end
+  private :marshal_load
 
   def <=>(other)
     if imag == 0 && other.kind_of?(Numeric)