Rework loop compilation / flows (#644)

tests/compiler/loop-flow.ts

@@ -0,0 +1,83 @@
+export function whileReturn(): i32 {
+  while (true) {
+    return 1;
+  }
+}
+
+assert(whileReturn() == 1);
+
+export function whileThrow(): i32 {
+  while (true) {
+    throw new Error("term");
+  }
+}
+
+export function whileContinue(): i32 {
+  while (true) {
+    continue;
+  }
+}
+
+export function whileAny(a: i32): i32 {
+  while (true) {
+    if (a == 1) return 1;
+    else if (a == 2) throw new Error("term");
+    else continue;
+  }
+}
+
+assert(whileAny(1) == 1);
+
+export function forReturn(): i32 {
+  for (;;) {
+    return 1;
+  }
+}
+
+assert(forReturn() == 1);
+
+export function forThrow(): i32 {
+  for (;;) {
+    throw new Error("term");
+  }
+}
+
+export function forContinue(): i32 {
+  for (;;) {
+    continue;
+  }
+}
+
+export function forAny(a: i32): i32 {
+  for (;;) {
+    if (a == 1) return 1;
+    else if (a == 2) throw new Error("term");
+    else continue;
+  }
+}
+
+assert(forAny(1) == 1);
+
+export function doReturn(): i32 {
+  do {
+    return 1;
+  } while (true);
+}
+
+assert(doReturn() == 1);
+
+export function doThrow(): i32 {
+  do {
+    throw new Error("term");
+  } while (true);
+}
+
+export function doAny(a: i32): i32 {
+  do {
+    if (a == 1) return 1;
+    else if (a == 2) throw new Error("term");
+    else continue;
+  } while (true);
+}
+
+assert(doAny(1) == 1);