Re-enable ART code paths and tests for ASan that were disabled for Valgrind.

Test: SANITIZE_HOST=address ASAN_OPTIONS='detect_leaks=0' make test-art-host
Bug: 29282211
Change-Id: I127a8c11c7d3b778c8d538aec0782a10f042225c
diff --git a/libartbase/base/mem_map_test.cc b/libartbase/base/mem_map_test.cc
index 4a78bdc..c575c7a 100644
--- a/libartbase/base/mem_map_test.cc
+++ b/libartbase/base/mem_map_test.cc
@@ -471,9 +471,8 @@
   // cannot allocate in the 2GB-4GB region.
   TEST_DISABLED_FOR_MIPS();
 
-  // This test may not work under Valgrind.
-  // TODO: Valgrind is no longer supported, but Address Sanitizer is:
-  // check whether this test works with ASan.
+  // This test does not work under AddressSanitizer.
+  // Historical note: This test did not work under Valgrind either.
   TEST_DISABLED_FOR_MEMORY_TOOL();
 
   CommonInit();