test: ARM Assembly syntax test file

tests/syntax-tests/source/ARM Assembly/test.S

@@ -0,0 +1,55 @@
+.data
+
+.balign 4
+red: .word 0
+green: .word 0
+blue: .word 0
+
+.text
+.global grayscale
+.func grayscale
+
+grayscale:
+assign:
+  /* some comment */
+  ldr ip, addr_red
+  str r3, [ip]
+  ldr ip, addr_green
+  ldmfd r13!, {r3}
+  str r3, [ip]
+  ldr ip, addr_blue
+  ldmfd r13!, {r3}
+  str r3, [ip]
+  stmfd r13!, {r4-r8}
+  ldr ip, addr_red
+  ldr r3, [ip]
+  ldr ip, addr_green
+  ldr r4, [ip]
+  ldr ip, addr_blue
+  ldr r5, [ip] /* another comment */
+grayscale_loop:
+  ldrb r6, [r1]
+  mul r6, r3, r6
+  add r1, r1, #1
+  ldrb r7, [r1]
+  mul r7, r4, r7
+  add r1, r1, #1
+  ldrb r8, [r1]
+  mul r8, r5, r8
+  add r1, r1, #1
+  add r6, r6, r7
+  add r6, r6, r8
+  asr r6, r6, #8
+  str r6, [r2]
+  add r2, r2, #1
+  sub r0, r0, #1
+  cmp r0, #0
+  bne grayscale_loop
+  ldmfd r13!, {r4-r8}
+  stmfd r13!, {r0-r1}
+  bx lr
+
+addr_red: .word red
+addr_green: .word green
+addr_blue: .word blue
+