Add UBSan blacklist for <__tree> and <__hash_table>

We all know <__tree> and <__hash_table> have plenty of UB that UBSan faithfully
finds. I am working on fixing this. However the noisy output from these failures
prevent automatically detecting regressions elsewhere.

This patch adds a blacklist file for these failures so I can later set up a
UBSAN buildbot.

llvm-svn: 273104

libcxx/test/libcxx/test/config.py

@@ -617,9 +617,12 @@ class Configuration(object):
                 self.config.available_features.add('msan')
                 self.config.available_features.add('sanitizer-new-delete')
             elif san == 'Undefined':
+                blacklist = os.path.join(self.libcxx_src_root,
+                                         'test/ubsan_blacklist.txt')
                 self.cxx.flags += ['-fsanitize=undefined',
                                    '-fno-sanitize=vptr,function',
-                                   '-fno-sanitize-recover']
+                                   '-fno-sanitize-recover=all',
+                                   '-fsanitize-blacklist=' + blacklist]
                 self.cxx.compile_flags += ['-O3']
                 self.env['UBSAN_OPTIONS'] = 'print_stacktrace=1'
                 self.config.available_features.add('ubsan')

libcxx/test/ubsan_blacklist.txt

@@ -0,0 +1,2 @@
+fun:*__tree*
+fun:*__hash_table*