Fix regression: DocumentSymbol codec deadlock

[kubukoz]

This happened in #207. I noticed it during the upgrade from 0.0.22 to 0.0.23, and had to bisect my endpoints to find the one causing trouble - it's textDocument/documentSymbol.

Not sure what happened yet, but you should be seeing this job time out...

[kubukoz]

stuck thread stack:

"io-compute-7@27960" tid=0x233 nid=NA waiting
  java.lang.Thread.State: WAITING
	  at jdk.internal.misc.Unsafe.park(Unsafe.java:-1)
	  at java.util.concurrent.locks.LockSupport.park(LockSupport.java:221)
	  at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:754)
	  at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1099)
	  at java.util.concurrent.CountDownLatch.await(CountDownLatch.java:230)
	  at langoustine.lsp.structures.DocumentSymbol$.reader$lzyINIT123(structures.scala:2601)
	  at langoustine.lsp.structures.DocumentSymbol$.reader(structures.scala:2601)
	  at langoustine.lsp.codecs.structures_DocumentSymbolCodec.visitors$lzyINIT123$1(codecs.scala:2409)
	  - locked <0x720e> (a scala.runtime.LazyRef)
	  at langoustine.lsp.codecs.structures_DocumentSymbolCodec.visitors$123(codecs.scala:151)
	  at langoustine.lsp.codecs.structures_DocumentSymbolCodec.reader(codecs.scala:2409)
	  at langoustine.lsp.codecs.structures_DocumentSymbolCodec.reader$(codecs.scala:2407)
	  at langoustine.lsp.structures.DocumentSymbol$.reader$lzyINIT123(structures.scala:2601)
	  at langoustine.lsp.structures.DocumentSymbol$.reader(structures.scala:2601)
	  at langoustine.lsp.codecs.requests_textDocument_documentSymbol.outputReader(codecs.scala:587)
	  at langoustine.lsp.codecs.requests_textDocument_documentSymbol.outputReader$(codecs.scala:556)
	  at langoustine.lsp.requests.textDocument$documentSymbol$.outputReader$lzyINIT22(requests.scala:570)
	  at langoustine.lsp.requests.textDocument$documentSymbol$.outputReader(requests.scala:570)
	  at langoustine.lsp.jsonrpcIntegration$.handlerToEndpoint(JSONRPC.scala:55)
	  at langoustine.lsp.ImmutableLSPBuilder.handleRequest(ImmutableLSPBuilder.scala:43)
	  at tests.core.LSPTests$.$init$$$anonfun$3(LSPTests.scala:116)
	  at tests.core.LSPTests$$$Lambda/0x0000007002b27980.apply(Unknown Source:-1)
	  at scala.util.Try$.apply(Try.scala:217)
	  at weaver.Test$.pure(Test.scala:31)
	  at weaver.FunSuiteF.test$$anonfun$1(suites.scala:187)
	  at weaver.FunSuiteF$$Lambda/0x0000007002b26ec0.apply(Unknown Source:-1)
	  at weaver.FunSuiteF.pureSpec$$anonfun$1(suites.scala:197)
	  at weaver.FunSuiteF$$Lambda/0x0000007002b438c8.apply(Unknown Source:-1)

@keynmol you naughty boy, did you play with lazy vals again

[kubukoz]

it's gotta be the fact that DocumentSymbol is recursive. I reverted the creation of MyCaseClassReader and it helped, it must've been that.

We're back to "New anonymous class definition will be duplicated at each inline site", but I bet the anon class does something to the initialization of the lazy val that makes it unstuck...

[kubukoz]

d'oh, it was just that the laziness of visitors was lost in the refactor - fixed. The other changes are just for style reasons

[keynmol]

Whoops, nice catch!