create fallback gtest subproject dependency

Allows project to be built and tested locally.

Signed-off-by: Zane Shelley <zshelle@us.ibm.com>
Change-Id: I0965581e5b2bc006a0edfcd05a6fea996f3f6ec2
diff --git a/test/simulator/meson.build b/test/simulator/meson.build
index 82e2336..87b2d80 100644
--- a/test/simulator/meson.build
+++ b/test/simulator/meson.build
@@ -7,13 +7,9 @@
 
 subdir('testcases')
 
-gtest = dependency('gtest', main : true, required : false, method : 'system')
-
 # Build simulator linked locally
-if gtest.found()
-    test('simulator',
-         executable('simulator', sim_src, test_src,
-                    dependencies : gtest,
-                    link_with : libhei_static,
-                    include_directories: [ incdir, '.' ]))
-endif
+test('simulator',
+     executable('simulator', sim_src, test_src,
+                dependencies : gtest_dep,
+                link_with : libhei_static,
+                include_directories: [ incdir, '.' ]))