The command below produces an error in powershell.exe:
arm-none-eabi-gcc   -mthumb    -mcpu=cortex-m4     -march=armv7e-m    -save-temps  -nostdlib 
  -O0   -Wl,-Map,"app.map"   -Wl,-T"tm4c123gh6pm.lds"    app_main.c  app_2.c -o  app_output.elf

It does however work without error in cmd.
 
    