turn test files in one function definition

lisc/test/loop.ssa

@@ -1,14 +1,16 @@
 # simple looping program
 # sums all integers from 100 to 0
 
-@start
+function $test {
+ @start
 
-@loop
+ @loop
 	%s  =w phi @start 100, @loop %s1
 	%n  =w phi @start   0, @loop %n1
 	%n1 =w sub %n, 1
 	%s1 =w add %s, %n
 	jnz %n1, @loop, @end
 
-@end
+ @end
 	ret
+}