Make RbExceptionFormatter#format error tolerant

[kateinoigakukun]

Ruby exceptions can be raised during formatting exceptions, so the formatting logic can be infinitely recursion and it makes the backtrace difficult to read.

Here is an example crash log for such case.

...
Crashed while printing bug report
Crashed while printing bug report
Crashed while printing bug report
...
at RbAbiGuest.apply [as rbVmBugreport] (dist/cjs/index.js:63:44)
at rbVmBugreport (dist/cjs/index.js:550:18)
at wrapRbOperation (dist/cjs/index.js:563:12)
at RbValue.callRbMethod [as call] (dist/cjs/index.js:419:28)
at RbExceptionFormatter.call [as format] (dist/cjs/index.js:489:33)
at format (dist/cjs/index.js:535:64)
at checkStatusTag (dist/cjs/index.js:565:9)
at body (dist/cjs/index.js:542:16)
at wrapRbOperation (dist/cjs/index.js:563:12)
at RbValue.callRbMethod [as call] (dist/cjs/index.js:419:28)
at RbExceptionFormatter.call [as format] (dist/cjs/index.js:489:33)
at format (dist/cjs/index.js:535:64)
at checkStatusTag (dist/cjs/index.js:565:9)
at body (dist/cjs/index.js:542:16)
at wrapRbOperation (dist/cjs/index.js:563:12)
at RbValue.callRbMethod [as call] (dist/cjs/index.js:419:28)
at RbExceptionFormatter.call [as format] (dist/cjs/index.js:489:33)
at format (dist/cjs/index.js:535:64)
at checkStatusTag (dist/cjs/index.js:565:9)
at body (dist/cjs/index.js:542:16)
...