AVR: ipa/92606 - Don't optimize PROGMEM data against non-PROGMEM.

ipa/92606: Inter-procedural analysis optimizes data across
address-spaces and PROGMEM.  As of v14, the PROGMEM part is
still not fixed (and there is still no target hook as proposed
in PR92932).  Just disable respective bogus optimization.

	PR ipa/92606
gcc/
	* config/avr/avr.cc (avr_option_override): Set
	flag_ipa_icf_variables = 0.
gcc/testsuite/
	* gcc.target/avr/torture/pr92606.c: New test.

(cherry picked from commit 08e752e)

Author: sprintersb

gcc/config/avr/avr.cc

@@ -1112,6 +1112,12 @@ avr_option_override (void)
   if (targetm.addr_space.zero_address_valid (ADDR_SPACE_GENERIC))
     flag_delete_null_pointer_checks = 0;
 
+  /* PR ipa/92606: Inter-procedural analysis optimizes data across
+     address-spaces and PROGMEM.  As of v14, the PROGMEM part is
+     still not fixed (and there is still no target hook as proposed
+     in PR92932).  Just disable respective bogus optimization.  */
+  flag_ipa_icf_variables = 0;
+
   if (flag_pic == 1)
     warning (OPT_fpic, "%<-fpic%> is not supported");
   if (flag_pic == 2)