Remove _spectator_calls method with filter

spec/spectator/mocks/double_spec.cr

@@ -355,7 +355,7 @@ Spectator.describe Spectator::Double do
     it "stores arguments for a call" do
       dbl.foo(42)
       args = Spectator::Arguments.capture(42)
-      call = dbl._spectator_calls(:foo).first
+      call = dbl._spectator_calls.first
       expect(call.arguments).to eq(args)
     end
   end

spec/spectator/mocks/lazy_double_spec.cr

@@ -297,7 +297,7 @@ Spectator.describe Spectator::LazyDouble do
     it "stores arguments for a call" do
       dbl.foo(42)
       args = Spectator::Arguments.capture(42)
-      call = dbl._spectator_calls(:foo).first
+      call = dbl._spectator_calls.first
       expect(call.arguments).to eq(args)
     end
   end

spec/spectator/mocks/null_double_spec.cr

@@ -324,7 +324,7 @@ Spectator.describe Spectator::NullDouble do
     it "stores arguments for a call" do
       dbl.foo(42)
       args = Spectator::Arguments.capture(42)
-      call = dbl._spectator_calls(:foo).first
+      call = dbl._spectator_calls.first
       expect(call.arguments).to eq(args)
     end
   end

src/spectator/mocks/double.cr

@@ -121,10 +121,6 @@ module Spectator
       @calls
     end
 
-    def _spectator_calls(method : Symbol) : Enumerable(MethodCall)
-      @calls.select { |call| call.method == method }
-    end
-
     # Returns the double's name formatted for user output.
     private def _spectator_stubbed_name : String
       {% if anno = @type.annotation(StubbedName) %}

src/spectator/mocks/mocked.cr

@@ -22,9 +22,6 @@ module Spectator
     # Retrieves an mutable collection of stubs.
     abstract def _spectator_stubs
 
-    # Retrieves an mutable collection of calls to stubs.
-    abstract def _spectator_calls
-
     def _spectator_define_stub(stub : ::Spectator::Stub) : Nil
       _spectator_stubs.unshift(stub)
     end

src/spectator/mocks/stubbable.cr

@@ -34,8 +34,8 @@ module Spectator
     # Saves a call that was made to a stubbed method.
     abstract def _spectator_record_call(call : MethodCall) : Nil
 
-    # Retrieves all previously saved calls for the specified method.
-    abstract def _spectator_calls(method : Symbol) : Enumerable(MethodCall)
+    # Retrieves all previously saved calls.
+    abstract def _spectator_calls
 
     # Method called when a stub isn't found.
     #