RFR: [9] Remove .jcheck from hotspot

[Aleksey Shipilev]

Remove .jcheck from hotspot repo, otherwise this prevents checking out sh/jdk9 when jcheck hook is
enabled.

$ hg diff
diff -r 83a69ba46054 .jcheck/conf
--- a/.jcheck/conf	Tue Dec 05 17:31:55 2017 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,2 +0,0 @@
-project=jdk9
-bugids=dup


sh/jdk8 got that from aarch64/jdk8u seed:
  http://hg.openjdk.java.net/aarch64-port/jdk8u/hotspot/rev/4c3f7e682e48
  http://hg.openjdk.java.net/shenandoah/jdk8u/hotspot/rev/4c3f7e682e48

sh/jdk10 would stay with jcheck for a time being

Thanks,
-Aleksey