Compile front-end (#476)

* fix tests for linux

* make a move on compile

* basic compile scaffold works

* compile binding

* clean

* fix

* fix grad, more tests

* basic python tests

* fix segfault on python exit

* compile works with python closures

* fix test

* fix python globals bug, and erase

* simplify

* more cpp tests

* bug fix with move function and compile at exit

* simplify inputs also

* enable and disable compiler

* remove simplify

* simplify tests use compile now

* fix multi-output with compile

* clear output tree from cache when function goes out of scope

* ../python/src/transforms.cpp

* remove closure capture

* comments

tests/CMakeLists.txt

@@ -20,11 +20,11 @@ target_sources(tests PRIVATE
   arg_reduce_tests.cpp
   autograd_tests.cpp
   blas_tests.cpp
+  compile_tests.cpp
   creations_tests.cpp
   device_tests.cpp
   eval_tests.cpp
   fft_tests.cpp
-  graph_optimize_tests.cpp
   load_tests.cpp
   ops_tests.cpp
   random_tests.cpp