[libfuzzer] Removing coverage-related flags from asan options.

Summary:
Reasons to remove are twofold:
 - we don't really need coverage=1 for libfuzzer operation
 - makes controlling coverage for fuzzer processes non-trivial.

Differential Revision: http://reviews.llvm.org/D17168

llvm-svn: 260611

llvm/lib/Fuzzer/FuzzerSanitizerOptions.cpp

@@ -10,10 +10,8 @@
 // Options reside in a separate file, so if we don't want to set the default
 // options we simply do not link this file in.
 // ASAN options:
-//   * don't dump the coverage to disk.
-//   * enable coverage by default.
 //   * enable handle_abort.
 //===----------------------------------------------------------------------===//
 extern "C" const char *__asan_default_options() {
-  return "coverage_pcs=0:coverage=1:handle_abort=1";
+  return "handle_abort=1";
 }