add function assignment

tests/anonymous_function.ar

@@ -0,0 +1 @@
+term.log(()=10)

tests/env.ar

@@ -0,0 +1 @@
+term.log("hello,", env.USER+'.', 'how is', env.XDG_SESSION_TYPE+'?')

tests/iteration-test.ar

@@ -1,4 +1,4 @@
-term.log(global."hello world")
+term.log(global)
 let i = 1e8
 while (i) do
   i=i-1

tests/number-memory-leak.ar

@@ -0,0 +1,6 @@
+let i = 10
+let x = 1
+while (i) do
+     x = x * 1e100000000
+     term.log(i=i-1)
+term.log(x)