Port EC test from Daala.

This currently only ports a small portion - the random encode/decode mixing
CDFs and bools, plus the patch initial bits tests.

The tests will break with a different CDF_PROB_TOP, as well as a different
CDF_PROB_TOP between bools and CDFs.

Change-Id: Ia289c6afd70cbc7dde5ed7a9c7c42f219c29935d
diff --git a/test/test.cmake b/test/test.cmake
index 589c4ab..8e87c94 100644
--- a/test/test.cmake
+++ b/test/test.cmake
@@ -293,7 +293,8 @@
     set(AOM_UNIT_TEST_COMMON_SOURCES
         ${AOM_UNIT_TEST_COMMON_SOURCES}
         "${AOM_ROOT}/test/binary_codes_test.cc"
-        "${AOM_ROOT}/test/boolcoder_test.cc")
+        "${AOM_ROOT}/test/boolcoder_test.cc"
+        "${AOM_ROOT}/test/ec_test.cc")
 
     if (CONFIG_EXT_TILE)
       set(AOM_UNIT_TEST_COMMON_SOURCES