[hwasan] Support __lsan_default_options

[MaskRay]

simplify code

if this is approved, consider simplifying asan_flags.cpp as well

[vitalybuka]

compiler-rt/test/lsan/TestCases/default_options.cpp

5

compiler-rt/lib/hwasan/hwasan.cpp

#if HWASAN_CONTAINS_UBSAN
   FlagParser ubsan_parser;
   __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
   RegisterCommonFlags(&ubsan_parser);
 #endif
 
   // Override from user-specified string.
   if (__hwasan_default_options)
     parser.ParseString(__hwasan_default_options());
+#if CAN_SANITIZE_LEAKS
+  lsan_parser.ParseString(__lsan_default_options());
+#endif
 #if HWASAN_CONTAINS_UBSAN
   const char *ubsan_default_options = __ubsan_default_options();
   ubsan_parser.ParseString(ubsan_default_options);
 #endif
 
   parser.ParseStringFromEnv("HWASAN_OPTIONS");
 #if CAN_SANITIZE_LEAKS
   lsan_parser.ParseStringFromEnv("LSAN_OPTIONS");

compiler-rt/test/lsan/TestCases/default_options.cpp

 // RUN: %clangxx_lsan -O2 %s -o %t && %run %t 2>&1 | FileCheck %s
 
-// Fixme: remove once test passes with hwasan
-// UNSUPPORTED: hwasan
-
 extern "C"
 const char *__lsan_default_options() {
-  // CHECK: Available flags for {{Leak|Address}}Sanitizer:
+  // CHECK: Available flags for {{Leak|Address|HWAddress}}Sanitizer:
   return "verbosity=1 help=1";
 }
 
 int main() {
   return 0;
 }