Add ohos ident flag for x86_64 library compile and fix x86 compile error

fixed 3a9781c4 from https://gitee.com/shawshank506/third_party_musl/pulls/572
fixed x86 compile from :https://gitee.com/openharmony/third_party_musl/pulls/667

Change-Id: Ib980b4d783087a48cd1d8e008726dbcc5db7e317
Signed-off-by: Nhaotuo <haotuo@huawei.com>

musl_src.gni

@@ -2131,6 +2131,8 @@ musl_src_porting_file = [
   "src/time/gettimeofday.c",
   "src/time/time.c",
   "src/stdio/__fdopen.c",
+  "src/linux/cache.c",
+  "src/sched/sched_getcpu.c",
 ]
 
 musl_inc_hook_files = [

porting/linux/user/crt/x86_64/crti.s

+.include "crtbrand.s"
+
+.section .init
+.global _init
+_init:
+	push %rax
+
+.section .fini
+.global _fini
+_fini:
+	push %rax

porting/linux/user/src/linux/cache.c

+/* Copyright (c) 2021-2022 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	 http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include "syscall.h"
+#include "atomic.h"
+
+#ifdef SYS_cacheflush
+int _flush_cache(void *addr, int len, int op)
+{
+	return syscall(SYS_cacheflush, addr, len, op);
+}
+weak_alias(_flush_cache, cacheflush);
+#endif
+
+#ifdef SYS_cachectl
+int __cachectl(void *addr, int len, int op)
+{
+	return syscall(SYS_cachectl, addr, len, op);
+}
+weak_alias(__cachectl, cachectl);
+#endif
+
+#ifdef SYS_riscv_flush_icache
+
+#define VDSO_FLUSH_ICACHE_SYM "__vdso_flush_icache"
+#define VDSO_FLUSH_ICACHE_VER "LINUX_4.5"
+
+static void *volatile vdso_func;
+
+static int flush_icache_init(void *start, void *end, unsigned long int flags)
+{
+        __get_vdso_info();
+	void *p = __get_vdso_addr(VDSO_FLUSH_ICACHE_VER, VDSO_FLUSH_ICACHE_SYM);
+	int (*f)(void *, void *, unsigned long int) =
+		(int (*)(void *, void *, unsigned long int))p;
+	a_cas_p(&vdso_func, (void *)flush_icache_init, p);
+	return f ? f(start, end, flags) : -ENOSYS;
+}
+
+static void *volatile vdso_func = (void *)flush_icache_init;
+
+int __riscv_flush_icache(void *start, void *end, unsigned long int flags) 
+{
+	int (*f)(void *, void *, unsigned long int) =
+		(int (*)(void *, void *, unsigned long int))vdso_func;
+	if (f) {
+		int r = f(start, end, flags);
+		if (!r) return r;
+		if (r != -ENOSYS) return __syscall_ret(r);
+	}
+}
+weak_alias(__riscv_flush_icache, riscv_flush_icache);
+#endif

porting/linux/user/src/sched/sched_getcpu.c

+/* Copyright (c) 2021-2022 Huawei Device Co., Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	 http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <sched.h>
+#include "syscall.h"
+#include "atomic.h"
+
+#ifdef VDSO_GETCPU_SYM
+
+static void *volatile vdso_func;
+
+typedef long (*getcpu_f)(unsigned *, unsigned *, void *);
+
+static long getcpu_init(unsigned *cpu, unsigned *node, void *unused)
+{
+        __get_vdso_info();
+	void *p = __get_vdso_addr(VDSO_GETCPU_VER, VDSO_GETCPU_SYM);
+	getcpu_f f = (getcpu_f)p;
+	a_cas_p(&vdso_func, (void *)getcpu_init, p);
+	return f ? f(cpu, node, unused) : -ENOSYS;
+}
+
+static void *volatile vdso_func = (void *)getcpu_init;
+
+#endif
+
+int sched_getcpu(void)
+{
+	int r;
+	unsigned cpu;
+
+#ifdef VDSO_GETCPU_SYM
+	getcpu_f f = (getcpu_f)vdso_func;
+	if (f) {
+		r = f(&cpu, 0, 0);
+		if (!r) return cpu;
+		if (r != -ENOSYS) return __syscall_ret(r);
+	}
+#endif
+
+	r = __syscall(SYS_getcpu, &cpu, 0, 0);
+	if (!r) return cpu;
+	return __syscall_ret(r);
+}