issue #198 add another test for sieve - but using while loop

(cherry picked from commit a3bf9dc10e)

tests/comptests/17_iarray_sieve.lua

@@ -0,0 +1,38 @@
+local sieve = compiler.load([[
+	local i: integer, k: integer, prime: integer, count: integer
+	local flags: integer[] = table.intarray(8190)
+
+    local iter: integer = 0
+	while iter <= 100000  do
+		count = 0
+		i = 0
+		while i <= 8190 do
+			flags[i] = 1
+			i = i + 1
+		end
+		i = 0
+		while i <= 8190 do
+			if flags[i] == 1 then
+				prime = i + i + 3;
+				k = i + prime
+				while k <= 8190 do
+					flags[k] = 0
+					k = k + prime
+				end
+				count = count + 1
+			end
+			i = i + 1
+		end
+		iter = iter + 1
+	end
+	return count
+]]
+)
+assert(sieve and type(sieve) == 'function')
+
+local t1 = os.clock()
+local count = sieve()
+local t2 = os.clock()
+print("time taken ", t2-t1)
+print(count)
+assert(count == 1899)