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.