[simulator] 修复 linux simulator 编译运行失败

components/libc/compilers/common/SConscript

@@ -11,6 +11,8 @@ if rtconfig.PLATFORM in ['armcc', 'armclang']:
     CPPDEFINES += ['__CLK_TCK=RT_TICK_PER_SECOND']
 elif rtconfig.PLATFORM in ['iccarm']:
     CPPDEFINES += ['CLOCKS_PER_SEC=RT_TICK_PER_SECOND'] # forcly revert to 1 by IAR
+elif rtconfig.PLATFORM in ['gcc'] and rtconfig.CPU in ['posix']:
+    CPPDEFINES += ['_GNU_SOURCE'] # linux x86 platform gcc use!
 
 src += Glob('*.c')
 

components/libc/compilers/common/ctime.c

@@ -66,6 +66,7 @@ static const short __spm[13] =
 rt_align(4) static const char *days = "Sun Mon Tue Wed Thu Fri Sat ";
 rt_align(4) static const char *months = "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ";
 
+#ifndef __isleap
 static int __isleap(int year)
 {
     /* every fourth year is a leap year except for century years that are
@@ -73,6 +74,7 @@ static int __isleap(int year)
     /*  return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)); */
     return (!(year % 4) && ((year % 100) || !(year % 400)));
 }
+#endif
 
 static void num2str(char *c, int i)
 {

components/libc/compilers/common/include/sys/time.h

@@ -48,6 +48,33 @@ struct timezone
     int tz_dsttime;       /* type of dst correction */
 };
 
+#if defined(_GNU_SOURCE) && (defined(__x86_64__) || defined(__i386__))
+/* linux x86 platform gcc use! */
+#define _TIMEVAL_DEFINED
+/* Values for the first argument to `getitimer' and `setitimer'.  */
+enum __itimer_which
+{
+    /* Timers run in real time.  */
+    ITIMER_REAL = 0,
+#define ITIMER_REAL ITIMER_REAL
+    /* Timers run only when the process is executing.  */
+    ITIMER_VIRTUAL = 1,
+#define ITIMER_VIRTUAL ITIMER_VIRTUAL
+    /* Timers run when the process is executing and when
+       the system is executing on behalf of the process.  */
+    ITIMER_PROF = 2
+#define ITIMER_PROF ITIMER_PROF
+};
+
+struct itimerval
+{
+    /* Value to put into `it_value' when the timer expires.  */
+    struct timeval it_interval;
+    /* Time to the next timer expiration.  */
+    struct timeval it_value;
+};
+#endif /* defined(_GNU_SOURCE) && (defined(__x86_64__) || defined(__i386__)) */
+
 #ifndef _TIMEVAL_DEFINED
 #define _TIMEVAL_DEFINED
 struct timeval