Clean up more test configurations (Part 2).

Remove the following configurations, as they are disabled on
our continuous testing infrastructure:
- art-interpreter-gcstress
- art-optimizing-gcstress
- art-jit-gcstress
- art-read-barrier
- art-read-barrier-gcstress

This CL should not be submitted before cl/213456896 is merged.

Test: n/a
Bug: 62611253
Change-Id: Ide02a5ea86bd22810d8efa3491fbd670fde2e3f1
diff --git a/test/testrunner/target_config.py b/test/testrunner/target_config.py
index 6f0d941..ad72945 100644
--- a/test/testrunner/target_config.py
+++ b/test/testrunner/target_config.py
@@ -70,40 +70,16 @@
                       '--gcstress',
                       '--gcverify']
     },
-    # TODO: Remove this configuration (which is a duplicate of
-    # 'art-interpreter-gcstress-gcverify') when it is no longer used by any
-    # continuous testing target (b/62611253).
-    'art-interpreter-gcstress' : {
-        'run-test' : ['--interpreter',
-                      '--gcstress',
-                      '--gcverify']
-    },
     'art-optimizing-gcstress-gcverify' : {
         'run-test' : ['--optimizing',
                       '--gcstress',
                       '--gcverify']
     },
-    # TODO: Remove this configuration (which is a duplicate of
-    # 'art-optimizing-gcstress-gcverify') when it is no longer used by any
-    # continuous testing target (b/62611253).
-    'art-optimizing-gcstress' : {
-        'run-test' : ['--optimizing',
-                      '--gcstress',
-                      '--gcverify']
-    },
     'art-jit-gcstress-gcverify' : {
         'run-test' : ['--jit',
                       '--gcstress',
                       '--gcverify']
     },
-    # TODO: Remove this configuration (which is a duplicate of
-    # 'art-jit-gcstress-gcverify') when it is no longer used by any
-    # continuous testing target (b/62611253).
-    'art-jit-gcstress' : {
-        'run-test' : ['--jit',
-                      '--gcstress',
-                      '--gcverify']
-    },
     'art-jit-on-first-use-gcstress' : {
         'run-test' : ['--jit',
                       '--gcstress',
@@ -116,29 +92,6 @@
             'ART_HEAP_POISONING' : 'true'
         }
     },
-    # TODO: Remove this configuration (which is a duplicate of
-    # 'art-read-barrier-heap-poisoning') when it is no longer used by any
-    # continuous testing target (b/62611253).
-    'art-read-barrier' : {
-        'run-test': ['--interpreter',
-                     '--optimizing'],
-        'env' : {
-            'ART_HEAP_POISONING' : 'true'
-        }
-    },
-    # TODO: Remove this configuration when it is no longer used by any
-    # continuous testing target (b/62611253). This configuration is scheduled
-    # for removal as it is now covered by 'art-interpreter-gcstress-gcverify'
-    # and 'art-optimizing-gcstress-gcverify' -- except for heap poisoning, but
-    # that's fine.
-    'art-read-barrier-gcstress' : {
-        'run-test' : ['--interpreter',
-                      '--optimizing',
-                      '--gcstress'],
-        'env' : {
-            'ART_HEAP_POISONING' : 'true'
-        }
-    },
     'art-read-barrier-table-lookup' : {
         'run-test' : ['--interpreter',
                       '--optimizing'],