third_party/libcxxabi: Add test suite (#1076)

Added the `libcxxabi` test suite as found in LLVM 17.0.6.

Some tests that do not apply to the current configuration of
comsopolitan are not added. These include:
- `backtrace_test`, `forced_unwind*`: Use unwind function unsupported in
SjLj mode.
- `noexception*`: Designed to test `libcxxabi` in no exceptions mode.

Some tests are added but not enabled due to bugs specific to GCC or
cosmopolitan. These are clearly indicated in the `BUILD.mk` file.

third_party/libcxxabi/test/unwind_06.pass.cc

@@ -0,0 +1,263 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: no-exceptions
+
+#include "third_party/libcxx/exception"
+#include "libc/isystem/stdlib.h"
+#include "libc/isystem/assert.h"
+#include "libc/stdio/stdio.h"
+
+// Suppress diagnostics about deprecated volatile operations
+#if defined(__GNUC__) && !defined(__clang__)
+# pragma GCC diagnostic ignored "-Wvolatile"
+#endif
+
+// Compile with -Os to get compiler uses float registers to hold float variables
+
+double get_(int x) { return (double)x; }
+
+double (* volatile get)(int) = get_;
+
+volatile int counter;
+
+double try1(bool v) {
+  double a = get(0);
+  double b = get(1);
+  for (counter = 100; counter; counter = counter - 1)
+    a += get(1) + b;
+  if (v) throw 10;
+  return get(0)+a+b;
+}
+
+double try2(bool v) {
+  double a = get(0);
+  double b = get(1);
+  double c = get(2);
+  for (counter = 100; counter; counter = counter - 1)
+    a += get(1) + b + c;
+  if (v) throw 10;
+  return get(0)+a+b+c;
+}
+
+double try3(bool v) {
+  double a = get(0);
+  double b = get(1);
+  double c = get(2);
+  double d = get(3);
+  for (counter = 100; counter; counter = counter - 1)
+    a += get(1) + b + c + d;
+  if (v) throw 10;
+  return get(0)+a+b+c+d;
+}
+
+double try4(bool v) {
+  double a = get(0);
+  double b = get(0);
+  double c = get(0);
+  double d = get(0);
+  double e = get(0);
+  for (counter = 100; counter; counter = counter - 1)
+    a += get(1) + b+c+d+e;
+  if (v) throw 10;
+  return get(0)+a+b+c+d+e;
+}
+
+double try5(bool v) {
+  double a = get(0);
+  double b = get(0);
+  double c = get(0);
+  double d = get(0);
+  double e = get(0);
+  double f = get(0);
+  for (counter = 100; counter; counter = counter - 1)
+    a += get(1) + b+c+d+e+f;
+  if (v) throw 10;
+  return get(0)+a+b+c+d+e+f;
+}
+
+double try6(bool v) {
+  double a = get(0);
+  double b = get(0);
+  double c = get(0);
+  double d = get(0);
+  double e = get(0);
+  double f = get(0);
+  double g = get(0);
+  for (counter = 100; counter; counter = counter - 1)
+    a += get(1) + b+c+d+e+f+g;
+  if (v) throw 10;
+  return get(0)+a+b+c+d+e+f+g;
+}
+
+double try7(bool v) {
+  double a = get(0);
+  double b = get(0);
+  double c = get(0);
+  double d = get(0);
+  double e = get(0);
+  double f = get(0);
+  double g = get(0);
+  double h = get(0);
+  for (counter = 100; counter; counter = counter - 1)
+    a += get(1) + b+c+d+e+f+g+h;
+  if (v) throw 10;
+  return get(0)+a+b+c+d+e+f+g+h;
+}
+
+double try8(bool v) {
+  double a = get(0);
+  double b = get(0);
+  double c = get(0);
+  double d = get(0);
+  double e = get(0);
+  double f = get(0);
+  double g = get(0);
+  double h = get(0);
+  double i = get(0);
+  for (counter = 100; counter; counter = counter - 1)
+    a += get(1) + b+c+d+e+f+g+h+i;
+  if (v) throw 10;
+  return get(0)+a+b+c+d+e+f+g+h+i;
+}
+
+
+
+
+
+double foo()
+{
+  double a = get(1);
+  double b = get(2);
+  double c = get(3);
+  double d = get(4);
+  double e = get(5);
+  double f = get(6);
+  double g = get(7);
+  double h = get(8);
+  try {
+    try1(true);
+  }
+  catch (int) {
+  }
+  assert(a == get(1));
+  assert(b == get(2));
+  assert(c == get(3));
+  assert(d == get(4));
+  assert(e == get(5));
+  assert(f == get(6));
+  assert(g == get(7));
+  assert(h == get(8));
+
+  try {
+    try2(true);
+  }
+  catch (int) {
+  }
+  assert(a == get(1));
+  assert(b == get(2));
+  assert(c == get(3));
+  assert(d == get(4));
+  assert(e == get(5));
+  assert(f == get(6));
+  assert(g == get(7));
+  assert(h == get(8));
+
+  try {
+    try3(true);
+  }
+  catch (int) {
+  }
+  assert(a == get(1));
+  assert(b == get(2));
+  assert(c == get(3));
+  assert(d == get(4));
+  assert(e == get(5));
+  assert(f == get(6));
+  assert(g == get(7));
+  assert(h == get(8));
+
+  try {
+    try4(true);
+  }
+  catch (int) {
+  }
+  assert(a == get(1));
+  assert(b == get(2));
+  assert(c == get(3));
+  assert(d == get(4));
+  assert(e == get(5));
+  assert(f == get(6));
+  assert(g == get(7));
+  assert(h == get(8));
+
+  try {
+    try5(true);
+  }
+  catch (int) {
+  }
+  assert(a == get(1));
+  assert(b == get(2));
+  assert(c == get(3));
+  assert(d == get(4));
+  assert(e == get(5));
+  assert(f == get(6));
+  assert(g == get(7));
+  assert(h == get(8));
+
+  try {
+    try6(true);
+  }
+  catch (int) {
+  }
+  assert(a == get(1));
+  assert(b == get(2));
+  assert(c == get(3));
+  assert(d == get(4));
+  assert(e == get(5));
+  assert(f == get(6));
+  assert(g == get(7));
+  assert(h == get(8));
+
+  try {
+    try7(true);
+  }
+  catch (int) {
+  }
+  assert(a == get(1));
+  assert(b == get(2));
+  assert(c == get(3));
+  assert(d == get(4));
+  assert(e == get(5));
+  assert(f == get(6));
+  assert(g == get(7));
+  assert(h == get(8));
+
+  try {
+    try8(true);
+  }
+  catch (int) {
+  }
+  assert(a == get(1));
+  assert(b == get(2));
+  assert(c == get(3));
+  assert(d == get(4));
+  assert(e == get(5));
+  assert(f == get(6));
+  assert(g == get(7));
+  assert(h == get(8));
+
+  return a+b+c+d+e+f+g+h;
+}
+
+
+
+int main(int, char**) {
+  foo();
+  return 0;
+}