support for NASM assembly synthax

hello.asm

@@ -0,0 +1,21 @@
+; ----------------------------------------------------------------------------------------
+; Writes "Hello, World" to the console using only system calls. Runs on 64-bit macOS only.
+; To assemble and run:
+;
+;     nasm -fmacho64 hello.asm && ld hello.o && ./a.out
+; ----------------------------------------------------------------------------------------
+
+          global    start
+
+          section   .text
+start:    mov       rax, 0x02000004         ; system call for write
+          mov       rdi, 1                  ; file handle 1 is stdout
+          mov       rsi, message            ; address of string to output
+          mov       rdx, 13                 ; number of bytes
+          syscall                           ; invoke operating system to do the write
+          mov       rax, 0x02000001         ; system call for exit
+          xor       rdi, rdi                ; exit code 0
+          syscall                           ; invoke operating system to exit
+
+          section   .data
+message:  db        "Hello, World", 10      ; note the newline at the end