[CI] Disable __tls_get_addr interception in asan

See google/sanitizers#1322. It might be
the cause of the intermittent asan failures on CI.

Author: glandium

CI/decision.py

@@ -97,6 +97,9 @@ def __init__(self, **kwargs):
                 'export GIT_CINNABAR_COVERAGE=1',
                 'export COVERAGE_FILE=$PWD/repo/.coverage',
             ] + command
+        if variant == 'asan':
+            kwargs.setdefault('env', {})['ASAN_OPTIONS'] = \
+                'intercept_tls_get_addr=0'
 
         if 'command' in kwargs:
             kwargs['command'] = command + kwargs['command']