Implement integer division operator

Fixes #107

hy/compiler.py

@@ -708,6 +708,7 @@ class HyASTCompiler(object):
     @builds("%")
     @builds("-")
     @builds("/")
+    @builds("//")
     @builds("*")
     @checkargs(min=2)
     def compile_maths_expression(self, expression):
@@ -717,6 +718,7 @@ class HyASTCompiler(object):
 
         ops = {"+": ast.Add,
                "/": ast.Div,
+               "//": ast.FloorDiv,
                "*": ast.Mult,
                "-": ast.Sub,
                "%": ast.Mod}

tests/native_tests/math.hy

@@ -29,6 +29,10 @@
   "NATIVE: Test division"
   (assert (= 25 (/ 100 2 2)))))
 
+(setv test_int_div (fn []
+  "NATIVE: Test integer division"
+  (assert (= 25 (// 101 2 2)))))
+
 (defn test-modulo []
   "NATIVE: test mod"
   (assert (= (% 10 2) 0)))