Move all simulator test cases to subdirectory

Signed-off-by: Zane Shelley <zshelle@us.ibm.com>
Change-Id: Id182f1afcff6f3506c36040d7dc590028b2ff5ee
diff --git a/test/simulator/testcases/meson.build b/test/simulator/testcases/meson.build
new file mode 100644
index 0000000..076a617
--- /dev/null
+++ b/test/simulator/testcases/meson.build
@@ -0,0 +1,6 @@
+# Test cases
+test_src = files(
+    'sample_test_case.cpp',
+    'exp20_foxhound7.cpp',
+)
+