NASM test for push [reg, r/m, imm] and pop reg are all tested

With ENABLE_JIT_ALWAYS set, it effectively tests all variants (is_32 +
imm/reg/rm) of the instruction.

Stack size variation should also be tested in the future.

See WASM dump for optimized versions here:

https://gist.github.com/AmaanC/c5c5f9d76bef589a7fbb0f4af3b15e64

tests/nasm/push.asm

@@ -0,0 +1,45 @@
+global _start
+
+section .data
+    align 16
+myquad:
+    dq	0x1234567890abcdef
+mydword:
+    dd	0xcafebabe
+myaddress:
+    dd	0xdeadbeef
+
+%include "header.inc"
+
+    ;; push r/m - push edx
+    db 0xff
+    db 0xf2
+
+    ;; push r/m - push bx
+    db 0x66
+    db 0xff
+    db 0xf3
+
+    push	0xdeadbeef
+    push	WORD 0xd00d
+    push	DWORD [myaddress]
+
+    lea	eax, [myaddress]
+    push	WORD [eax]
+
+    mov	ecx, 0xcafe
+    push	cx
+    push	ecx
+
+    xor	eax, eax
+
+    pop	ax
+    pop	eax
+    pop	cx
+    pop	ecx
+    pop	dx
+    pop	ebx
+    pop	si
+    pop	di
+
+%include "footer.inc"