Added several flow control tests.

test/misc/flow-while-01.c

@@ -0,0 +1,70 @@
+int a;
+
+static int f1(void)
+{
+    while (1) {
+        ++a;
+    }
+    /* Unreachable */
+    a = 2;
+    return a;
+}
+
+static int f2(void)
+{
+    while (1) {
+        ++a;
+        if (a == 5) break;
+    }
+    /* Reachable */
+    a = 2;
+    return a;
+}
+
+static int f3(void)
+{
+    while (1) {
+        ++a;
+        return a;
+    }
+    /* Unreachable */
+    a = 2;
+}
+
+static int f4(void)
+{
+    while (0) {
+        /* Unreachable */
+        ++a;
+        return a;
+    }
+    /* Reachable */
+    a = 2;
+    return 0;
+}
+
+static int f5(void)
+{
+    while (1) {
+        ++a;
+       	if (a == 4) goto L;
+        return a;
+    }
+    /* Reachable via L */
+L:  a = 2;
+}
+
+static int f6(void)
+{
+    while (0) { 
+	/* Unreachable but no warning */
+    }
+    a = 2;
+    return a;
+}
+
+int main(void)
+{
+    return f1() + f2() + f3() + f4() + f5() + f6();
+}
+