Merge pull request #1856 from xuzhuoyi/stm32f4xx-hal

[bsp][stm32f4xx-hal] Fix compile failure when using  ARM Compiler V6

bsp/stm32f4xx-HAL/drivers/board.h

@@ -370,7 +370,7 @@
 
 #define STM32_SRAM_END          (0x20000000 + STM32_SRAM_SIZE * 1024)
 
-#ifdef __CC_ARM
+#if defined(__CC_ARM) || defined(__CLANG_ARM)
     extern int Image$$RW_IRAM1$$ZI$$Limit;
     #define HEAP_BEGIN  ((void *)&Image$$RW_IRAM1$$ZI$$Limit)
 #elif __ICCARM__