re PR target/71151 ([avr] -fmerge-constants and -fdata-sections/-ffunction-sections results in string constants in .progmem.gcc_sw section)

gcc/testsuite/
	PR target/71151
	* gcc.target/avr/pr71151-common.h (foo): Use macro SECTION_NAME
	instead of ".foo" for its section name.
	* gcc.target/avr/pr71151-2.c (SECTION_NAME): Define appropriately
	depending on MCU's flash size.
	* gcc.target/avr/pr71151-3.c (SECTION_NAME): Dito.
	* gcc.target/avr/pr71151-4.c (SECTION_NAME): Dito.
	* gcc.target/avr/pr71151-5.c (SECTION_NAME): Dito.
	* gcc.target/avr/pr71151-6.c (SECTION_NAME): Dito.
	* gcc.target/avr/pr71151-7.c (SECTION_NAME): Dito.
	* gcc.target/avr/pr71151-8.c (SECTION_NAME): Dito.

From-SVN: r237910