[BSP][smart] fix link script for smart in vexpress-a9 (#6764)

bsp/qemu-vexpress-a9/SConstruct

@@ -28,5 +28,9 @@ Export('rtconfig')
 # prepare building environment
 objs = PrepareBuilding(env, RTT_ROOT)
 
+if GetDepend('RT_USING_SMART'):
+    # use smart link.lds
+    env['LINKFLAGS'] = env['LINKFLAGS'].replace('link.lds', 'link_smart.lds')
+
 # make a building
 DoBuilding(TARGET, objs)

bsp/qemu-vexpress-a9/rtconfig.py

@@ -37,7 +37,7 @@ BUILD       = 'debug'
 LINK_SCRIPT = 'link.lds'
 
 if PLATFORM == 'gcc':
-    PREFIX  = os.getenv('RTT_EXEC_PREFIX') or 'arm-none-eabi-'
+    PREFIX  = os.getenv('RTT_CC_PREFIX') or 'arm-none-eabi-'
     CC      = PREFIX + 'gcc'
     CXX     = PREFIX + 'g++'
     AS      = PREFIX + 'gcc'
@@ -66,7 +66,7 @@ if PLATFORM == 'gcc':
     else:
         CFLAGS   += ' -Os'
         CXXFLAGS += ' -Os'
-    CXXFLAGS += ' -Woverloaded-virtual -fno-exceptions -fno-rtti'
+    CXXFLAGS += ' -Woverloaded-virtual -fno-rtti'
 
     M_CFLAGS = CFLAGS + ' -mlong-calls -fPIC '
     M_CXXFLAGS = CXXFLAGS + ' -mlong-calls -fPIC'

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

@@ -40,6 +40,8 @@ extern "C" {
 #define DST_TUR     9   /* Turkey */
 #define DST_AUSTALT 10  /* Australian style with shift in 1986 */
 
+struct itimerspec;
+
 struct timezone
 {
     int tz_minuteswest;   /* minutes west of Greenwich */