x86: Add missing .note.GNU-stack to assembly source

Add .note.GNU-stack assembly source to avoid linker warning:

ld: warning: /tmp/ccPZSZ7Z.o: missing .note.GNU-stack section implies executable stack
ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
FAIL: gcc.target/i386/iamcu/test_3_element_struct_and_unions.c compilation,  -O0

	PR testsuite/105433
	* gcc.target/i386/iamcu/asm-support.S: Add .note.GNU-stack.
	* gcc.target/x86_64/abi/asm-support.S: Likewise.
	* gcc.target/x86_64/abi/avx/asm-support.S: Likewise.
	* gcc.target/x86_64/abi/avx512f/asm-support.S: Likewise.
	* gcc.target/x86_64/abi/avx512fp16/asm-support.S: Likewise.
	* gcc.target/x86_64/abi/avx512fp16/m256h/asm-support.S: Likewise.
	* gcc.target/x86_64/abi/avx512fp16/m512h/asm-support.S: Likewise.
	* gcc.target/x86_64/abi/ms-sysv/do-test.S: Likewise.