Fixed _clearcache implementation

Failed to compile for Android - there was a mess with register variables

Author: vhbit

lib/builtins/clear_cache.c

@@ -49,12 +49,12 @@ __clear_cache(void* start, void* end)
 
         sysarch(ARM_SYNC_ICACHE, &arg);
     #elif defined(ANDROID)
-         const register int start_reg __asm("r0") = (int) (intptr_t) start;
+         register int start_reg __asm("r0") = (int) (intptr_t) start;
          const register int end_reg __asm("r1") = (int) (intptr_t) end;
          const register int flags __asm("r2") = 0;
          const register int syscall_nr __asm("r7") = __ARM_NR_cacheflush;
         __asm __volatile("svc 0x0" : "=r"(start_reg)
-            : "r"(syscall_nr), "r"(start_reg), "r"(end_reg), "r"(flags) : "r0");
+            : "r"(syscall_nr), "r"(start_reg), "r"(end_reg), "r"(flags));
          if (start_reg != 0) {
              compilerrt_abort();
          }