Raise error for JSON overflow encoding in Ruby (#5752)

* add check for overflow

* de-nestify

* break long lines
diff --git a/ruby/Rakefile b/ruby/Rakefile
index 79b7df3..140f5e5 100644
--- a/ruby/Rakefile
+++ b/ruby/Rakefile
@@ -118,11 +118,11 @@
 end
 
 file "tests/basic_test.rb" => "tests/basic_test.proto" do |file_task|
-  sh "../src/protoc --ruby_out=. tests/basic_test.proto"
+  sh "../src/protoc -I../src -I. --ruby_out=. tests/basic_test.proto"
 end
 
 file "tests/basic_test_proto2.rb" => "tests/basic_test_proto2.proto" do |file_task|
-  sh "../src/protoc --ruby_out=. tests/basic_test_proto2.proto"
+  sh "../src/protoc -I../src -I. --ruby_out=. tests/basic_test_proto2.proto"
 end
 
 task :genproto => genproto_output