libroot: Call abort() instead of debugger() from assert().

As per the POSIX specification.

This gives the calling program a chance to catch the assertion. But
in the case where no signal handler is installed for SIGABRT, we
will call debugger() anyway and present as a crash as before.

Fixes #10295.

src/system/libroot/posix/assert.c

@@ -1,7 +1,7 @@
-/* 
-** Copyright 2004, Axel Dörfler, [email protected]. All rights reserved.
-** Distributed under the terms of the Haiku License.
-*/
+/*
+ * Copyright 2004, Axel Dörfler, [email protected]. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
 
 
 #undef NDEBUG
@@ -22,7 +22,7 @@ __assert_fail(const char *assertion, const char *file,
 	unsigned int line, const char *function)
 {
 	fprintf(stderr, "%s: %s:%d:%s: %s\n", __progname, file, line, function, assertion);
-	debugger(assertion);
+	abort();
 }
 
 
@@ -31,5 +31,5 @@ __assert_perror_fail(int error, const char *file,
 	unsigned int line, const char *function)
 {
 	fprintf(stderr, "%s: %s:%d:%s: %s\n", __progname, file, line, function, strerror(error));
-	debugger(strerror(error));
+	abort();
 }