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/x86gprintrin.h

@@ -0,0 +1,63 @@
+/*===--------------- x86gprintrin.h - X86 GPR intrinsics ------------------===
+ *
+ * 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
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#ifndef __X86GPRINTRIN_H
+#define __X86GPRINTRIN_H
+
+#if !defined(__SCE__) || __has_feature(modules) || defined(__HRESET__)
+#include "hresetintrin.h"
+#endif
+
+#if !defined(__SCE__) || __has_feature(modules) || defined(__UINTR__)
+#include "uintrintrin.h"
+#endif
+
+#if !defined(__SCE__) || __has_feature(modules) || defined(__USERMSR__)
+#include "usermsrintrin.h"
+#endif
+
+#if !defined(__SCE__) || __has_feature(modules) || defined(__CRC32__)
+#include "crc32intrin.h"
+#endif
+
+#if !defined(__SCE__) || __has_feature(modules) || defined(__PRFCHI__)
+#include "prfchiintrin.h"
+#endif
+
+#if !defined(__SCE__) || __has_feature(modules) || defined(__RAOINT__)
+#include "raointintrin.h"
+#endif
+
+#if !defined(__SCE__) || __has_feature(modules) || defined(__CMPCCXADD__)
+#include "cmpccxaddintrin.h"
+#endif
+
+#if defined(__i386__)
+#define __SAVE_GPRBX "mov {%%ebx, %%eax |eax, ebx};"
+#define __RESTORE_GPRBX "mov {%%eax, %%ebx |ebx, eax};"
+#define __TMPGPR "eax"
+#else
+// When in 64-bit target, the 32-bit operands generate a 32-bit result,
+// zero-extended to a 64-bit result in the destination general-purpose,
+// It means "mov x %ebx" will clobber the higher 32 bits of rbx, so we
+// should preserve the 64-bit register rbx.
+#define __SAVE_GPRBX "mov {%%rbx, %%rax |rax, rbx};"
+#define __RESTORE_GPRBX "mov {%%rax, %%rbx |rbx, rax};"
+#define __TMPGPR "rax"
+#endif
+
+#define __SSC_MARK(__Tag)                                                      \
+  __asm__ __volatile__( __SAVE_GPRBX                                           \
+                       "mov {%0, %%ebx|ebx, %0}; "                             \
+                       ".byte 0x64, 0x67, 0x90; "                              \
+                        __RESTORE_GPRBX                                        \
+                       ::"i"(__Tag)                                            \
+                       :  __TMPGPR );
+
+#endif /* __X86GPRINTRIN_H */