Invalid assert(HeapBaseMinAddress > 0) in ReservedHeapSpace::initialize_compressed_heap

See http://hg.openjdk.java.net/jdk/jdk/file/2e928420389d/src/hotspot/share/memory/virtualspace.cpp#l493

void ReservedHeapSpace::initialize_compressed_heap(const size_t size, size_t alignment, bool large) {
...
  assert(HeapBaseMinAddress > 0, "sanity"); //<<<< HERE

==========

# This is OK
$ java -XX:HeapBaseMinAddress=0 -version

# This crashes with a fastdebug JVM
$ java -Xmx1024m -XX:HeapBaseMinAddress=0

# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/virtualspace.cpp:493
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/home/iklam/jdk/abe/open/src/hotspot/share/memory/virtualspace.cpp:493), pid=20182, tid=20183
# assert(HeapBaseMinAddress > 0) failed: sanity

==========

http://hg.openjdk.java.net/jdk/jdk/file/2e928420389d/src/hotspot/share/runtime/arguments.cpp#l1768

There is code that ensures HeapBaseMinAddress >= DefaultHeapBaseMinAddress, but that happens only when MaxHeapSize is default, so the assert doesn't match the existing behavior.

The JVM works just fine if we remove the assert.