[EH] Increment uncaughtExceptionCount in __cxa_rethrow_primary_exception (#26527)

This was missing, causing `std::uncaught_exceptions()` to return
incorrect values.

Author: aheejin

src/lib/libexceptions.js

@@ -226,6 +226,7 @@ var LibraryExceptions = {
     var info = new ExceptionInfo(ptr);
     info.set_rethrown(true);
     info.set_caught(false);
+    uncaughtExceptionCount++;
 #if !DISABLE_EXCEPTION_CATCHING
     ___cxa_increment_exception_refcount(ptr);
     exceptionLast = new CppException(ptr);

…/core/test_exceptions_uncaught_count.cpp test/core/test_exceptions_uncaught_3.cpptest/core/test_exceptions_uncaught_count.cpp renamed to test/core/test_exceptions_uncaught_3.cpp test/core/test_exceptions_uncaught_count.cpp renamed to test/core/test_exceptions_uncaught_3.cpp

@@ -0,0 +1,27 @@
+#include <stdexcept>
+#include <stdio.h>
+
+struct DestructorTester {
+  ~DestructorTester() {
+    printf("Destructor Uncaught: %d\n", std::uncaught_exceptions());
+  }
+};
+
+int main() {
+  std::exception_ptr p;
+  try {
+    throw std::runtime_error("test");
+  } catch (...) {
+    p = std::current_exception();
+  }
+
+  printf("Before Uncaught: %d\n", std::uncaught_exceptions());
+  try {
+    DestructorTester dt;
+    std::rethrow_exception(p);
+  } catch (...) {
+    printf("In catch Uncaught: %d\n", std::uncaught_exceptions());
+  }
+  printf("After Uncaught: %d\n", std::uncaught_exceptions());
+  return 0;
+}

…/core/test_exceptions_uncaught_count.out test/core/test_exceptions_uncaught_3.outtest/core/test_exceptions_uncaught_count.out renamed to test/core/test_exceptions_uncaught_3.out test/core/test_exceptions_uncaught_count.out renamed to test/core/test_exceptions_uncaught_3.out

@@ -0,0 +1,4 @@
+Before Uncaught: 0
+Destructor Uncaught: 1
+In catch Uncaught: 0
+After Uncaught: 0

test/core/test_exceptions_uncaught_4.cpp

@@ -1457,8 +1457,12 @@ def test_exceptions_rethrow(self):
     self.do_core_test('test_exceptions_rethrow.cpp')
 
   @with_all_eh_sjlj
-  def test_exceptions_uncaught_count(self):
-    self.do_core_test('test_exceptions_uncaught_count.cpp')
+  def test_exceptions_uncaught_3(self):
+    self.do_core_test('test_exceptions_uncaught_3.cpp')
+
+  @with_all_eh_sjlj
+  def test_exceptions_uncaught_4(self):
+    self.do_core_test('test_exceptions_uncaught_4.cpp')
 
   @with_all_eh_sjlj
   def test_exceptions_resume(self):