[compiler-rt] Include system headers before optionally defining HWCAP macros

[dim]

Summary

In https://reviews.llvm.org/D141285 the optional definitions of HWCAP
macros were moved to before their usage. However, they were also moved
to before the inclusion of system headers which can optionally define
them. If any of those system headers then actually defined any of the
HWCAP macros, it would result in a redefinition error.

Move the system header includes to just before the optional definitions,
to avoid this problem.

[ilinpv]

LGTM, thanks!

compiler-rt/lib/builtins/cpu_model.c

int CONSTRUCTOR_ATTRIBUTE __cpu_indicator_init(void) {
   assert(__cpu_model.__cpu_vendor < VENDOR_MAX);
   assert(__cpu_model.__cpu_type < CPU_TYPE_MAX);
   assert(__cpu_model.__cpu_subtype < CPU_SUBTYPE_MAX);
 
   return 0;
 }
 #elif defined(__aarch64__)
 
+// LSE support detection for out-of-line atomics
+// using HWCAP and Auxiliary vector
+_Bool __aarch64_have_lse_atomics
+    __attribute__((visibility("hidden"), nocommon));
+
+#if defined(__has_include)
+#if __has_include(<sys/auxv.h>)
+#include <sys/auxv.h>
+#if __has_include(<asm/hwcap.h>)
+#include <asm/hwcap.h>
+
+#if defined(__ANDROID__)
+#include <string.h>
+#include <sys/system_properties.h>
+#elif defined(__Fuchsia__)
+#include <zircon/features.h>
+#include <zircon/syscalls.h>
+#endif
+
 #ifndef AT_HWCAP
 #define AT_HWCAP 16
 #endif
 #ifndef HWCAP_CPUID
 #define HWCAP_CPUID (1 << 11)
 #endif
 #ifndef HWCAP_FP
 #define HWCAP_FP (1 << 0)

 #endif
 #ifndef HWCAP2_EBF16
 #define HWCAP2_EBF16 (1UL << 32)
 #endif
 #ifndef HWCAP2_SVE_EBF16
 #define HWCAP2_SVE_EBF16 (1UL << 33)
 #endif
 
-// LSE support detection for out-of-line atomics
-// using HWCAP and Auxiliary vector
-_Bool __aarch64_have_lse_atomics
-    __attribute__((visibility("hidden"), nocommon));
-
-#if defined(__has_include)
-#if __has_include(<sys/auxv.h>)
-#include <sys/auxv.h>
-#if __has_include(<asm/hwcap.h>)
-#include <asm/hwcap.h>
-
-#if defined(__ANDROID__)
-#include <string.h>
-#include <sys/system_properties.h>
-#elif defined(__Fuchsia__)
-#include <zircon/features.h>
-#include <zircon/syscalls.h>
-#endif
-
 // Detect Exynos 9810 CPU
 #define IF_EXYNOS9810                                                          \
   char arch[PROP_VALUE_MAX];                                                   \
   if (__system_property_get("ro.arch", arch) > 0 &&                            \
       strncmp(arch, "exynos9810", sizeof("exynos9810") - 1) == 0)
 
 static void CONSTRUCTOR_ATTRIBUTE init_have_lse_atomics(void) {
 #if defined(__FreeBSD__)