Improve chain completion by waiting for either main or context chains.

This will provide completions from either of the completions processing
threads that finish first. Most of the time it will be the main chain
completion thread. By doing this we try to minimize the chance we will
not get any chain completions when there supposed to be.

Author: gayanper

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/ChainCompletionProposalComputer.java

@@ -132,7 +132,7 @@ private List<CompletionItem> executeCallChainSearch() {
 					// ignore
 				}
 			}, executor);
-			CompletableFuture<Void> future = CompletableFuture.allOf(mainChains, contextChains);
+			CompletableFuture<?> future = CompletableFuture.anyOf(mainChains, contextChains);
 
 			long timeout = Long.parseLong(JavaManipulation.getPreference("recommenders.chain.timeout", cu.getJavaProject()));
 			future.get(timeout, TimeUnit.SECONDS);