[Kernel] Add ARMCC 6.x support.

components/libc/compilers/armlibc/mem_std.c

@@ -16,8 +16,11 @@
 #include "rtthread.h"
 
 #ifdef RT_USING_HEAP
+
+#ifdef __CC_ARM
 /* avoid the heap and heap-using library functions supplied by arm */
 #pragma import(__use_no_heap)
+#endif
 
 void *malloc(size_t n)
 {

components/libc/compilers/armlibc/stubs.c

@@ -37,7 +37,11 @@
 #include "dfs_posix.h"
 #endif
 
+#ifdef __CLANG_ARM
+__asm(".global __use_no_semihosting\n\t");
+#else
 #pragma import(__use_no_semihosting_swi)
+#endif
 
 /* Standard IO device handles. */
 #define STDIN       0