Add specs for [Bug #20654]

Author: peterzhu2118

core/integer/shared/integer_ceil_precision.rb

@@ -32,5 +32,12 @@
       send(@method, -123).ceil(-2).should.eql?(-100)
       send(@method, -123).ceil(-3).should.eql?(0)
     end
+
+    ruby_bug "#20654", ""..."3.4" do
+      it "returns 10**precision.abs when precision.abs is larger than the number digits of self" do
+        send(@method, 123).ceil(-20).should.eql?(100000000000000000000)
+        send(@method, 123).ceil(-50).should.eql?(100000000000000000000000000000000000000000000000000)
+      end
+    end
   end
 end

core/integer/shared/integer_floor_precision.rb

@@ -32,5 +32,12 @@
       send(@method, -123).floor(-2).should.eql?(-200)
       send(@method, -123).floor(-3).should.eql?(-1000)
     end
+
+    ruby_bug "#20654", ""..."3.4" do
+      it "returns -(10**precision.abs) when self is negative and precision.abs is larger than the number digits of self" do
+        send(@method, -123).floor(-20).should.eql?(-100000000000000000000)
+        send(@method, -123).floor(-50).should.eql?(-100000000000000000000000000000000000000000000000000)
+      end
+    end
   end
 end