Reduce optimization opportunities in Semihosting.
Reduce optimization opportunities in Semihosting.

  * arch/ARM/cortex_m/src/semihosting.adb (Write_0): Data is of new
      type Byte_Array, which is a new UInt8_Array with volatile
      components (FSF GCC was miscompiling at -O3).

simonjwright/Ada_Drivers_Library,simonjwright/Ada_Drivers_Library,AdaCore/Ada_Drivers_Library,AdaCore/Ada_Drivers_Library