Upgrade to a Lucene 7 snapshot (#24089)

We want to upgrade to Lucene 7 ahead of time in order to be able to check whether it causes any trouble to Elasticsearch before Lucene 7.0 gets released. From a user perspective, the main benefit of this upgrade is the enhanced support for sparse fields, whose resource consumption is now function of the number of docs that have a value rather than the total number of docs in the index.

Some notes about the change:
 - it includes the deprecation of the `disable_coord` parameter of the `bool` and `common_terms` queries: Lucene has removed support for coord factors
 - it includes the deprecation of the `index.similarity.base` expert setting, since it was only useful to configure coords and query norms, which have both been removed
 - two tests have been marked with `@AwaitsFix` because of #23966, which we intend to address after the merge

Author: jpountz

buildSrc/src/main/resources/forbidden/es-all-signatures.txt

@@ -26,12 +26,6 @@ java.util.concurrent.ThreadLocalRandom
 
 java.security.MessageDigest#clone() @ use org.elasticsearch.common.hash.MessageDigests
 
-@defaultMessage this should not have been added to lucene in the first place
-org.apache.lucene.index.IndexReader#getCombinedCoreAndDeletesKey()
-
-@defaultMessage Soon to be removed
-org.apache.lucene.document.FieldType#numericType()
-
 @defaultMessage Don't use MethodHandles in slow ways, don't be lenient in tests.
 java.lang.invoke.MethodHandle#invoke(java.lang.Object[])
 java.lang.invoke.MethodHandle#invokeWithArguments(java.lang.Object[])

buildSrc/src/main/resources/forbidden/es-core-signatures.txt

@@ -36,16 +36,6 @@ org.apache.lucene.index.IndexReader#decRef()
 org.apache.lucene.index.IndexReader#incRef()
 org.apache.lucene.index.IndexReader#tryIncRef()
 
-@defaultMessage Close listeners can only installed via ElasticsearchDirectoryReader#addReaderCloseListener
-org.apache.lucene.index.IndexReader#addReaderClosedListener(org.apache.lucene.index.IndexReader$ReaderClosedListener)
-org.apache.lucene.index.IndexReader#removeReaderClosedListener(org.apache.lucene.index.IndexReader$ReaderClosedListener)
-
-@defaultMessage Pass the precision step from the mappings explicitly instead
-org.apache.lucene.search.LegacyNumericRangeQuery#newDoubleRange(java.lang.String,java.lang.Double,java.lang.Double,boolean,boolean)
-org.apache.lucene.search.LegacyNumericRangeQuery#newFloatRange(java.lang.String,java.lang.Float,java.lang.Float,boolean,boolean)
-org.apache.lucene.search.LegacyNumericRangeQuery#newIntRange(java.lang.String,java.lang.Integer,java.lang.Integer,boolean,boolean)
-org.apache.lucene.search.LegacyNumericRangeQuery#newLongRange(java.lang.String,java.lang.Long,java.lang.Long,boolean,boolean)
-
 @defaultMessage Only use wait / notify when really needed try to use concurrency primitives, latches or callbacks instead.
 java.lang.Object#wait()
 java.lang.Object#wait(long)

buildSrc/version.properties

@@ -1,6 +1,6 @@
 # When updating elasticsearch, please update 'rest' version in core/src/main/resources/org/elasticsearch/bootstrap/test-framework.policy
 elasticsearch     = 6.0.0-alpha1
-lucene            = 6.5.0
+lucene            = 7.0.0-snapshot-89f6d17
 
 # optional dependencies
 spatial4j         = 0.6

core/licenses/lucene-analyzers-common-6.5.0.jar.sha1

@@ -0,0 +1 @@
+e69234c2e898d86a53edbe8d22e33bebc45286cd

core/licenses/lucene-analyzers-common-7.0.0-snapshot-89f6d17.jar.sha1

@@ -0,0 +1 @@
+48172a8e1fe6562f55ab671d42af53652794d5df

core/licenses/lucene-backward-codecs-6.5.0.jar.sha1

@@ -0,0 +1 @@
+3dab251d4c7ab4ff5095e5f1d1e127ec2cf3c07d