Release Cosmopolitan v3.8.0

This change switches c++ exception handling from sjlj to standard dwarf.
It's needed because clang for aarch64 doesn't support sjlj. It turns out
that libunwind had a bare-metal configuration that made this easy to do.

This change gets the new experimental cosmocc -mclang flag in a state of
working so well that it can now be used to build all of llamafile and it
goes 3x faster in terms of build latency, without trading away any perf.

The int_fast16_t and int_fast32_t types are now always defined as 32-bit
in the interest of having more abi consistency between cosmocc -mgcc and
-mclang mode.

third_party/intel/clang/ptwriteintrin.h

@@ -0,0 +1,37 @@
+/*===------------ ptwriteintrin.h - PTWRITE intrinsic --------------------===
+ *
+ * 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
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#if !defined __X86INTRIN_H && !defined __IMMINTRIN_H
+#error "Never use <ptwriteintrin.h> directly; include <x86intrin.h> instead."
+#endif
+
+#ifndef __PTWRITEINTRIN_H
+#define __PTWRITEINTRIN_H
+
+/* Define the default attributes for the functions in this file. */
+#define __DEFAULT_FN_ATTRS \
+  __attribute__((__always_inline__, __nodebug__,  __target__("ptwrite")))
+
+static __inline__ void __DEFAULT_FN_ATTRS
+_ptwrite32(unsigned int __value) {
+  __builtin_ia32_ptwrite32(__value);
+}
+
+#ifdef __x86_64__
+
+static __inline__ void __DEFAULT_FN_ATTRS
+_ptwrite64(unsigned long long __value) {
+  __builtin_ia32_ptwrite64(__value);
+}
+
+#endif /* __x86_64__ */
+
+#undef __DEFAULT_FN_ATTRS
+
+#endif /* __PTWRITEINTRIN_H */