Add native build and compiler driver

descr

@@ -0,0 +1,7 @@
+delta
+A compiler for a small pure functional query language. Source programs declare
+record types, one keyed input collection, pure scalar helper functions and one
+collection query. The compiler infers types, specialises helpers, normalises to
+ANF, builds a collection dependency plan, and emits OCaml source containing
+query specific initialization and incremental update code. A reference
+interpreter and an incremental plan executor are used as correctness oracles.