checker: .byte directive inside an asm block is reported as the deprecated byte type #28739

Describe the bug

Inside an asm block, the assembler directive .byte is reported as the deprecated V type byte:

byte_directive.v:14:3: error: byte is deprecated, use u8 instead

The diagnostic comes from vlib/v/types/checker.v ('byte is deprecated, use u8 instead'), i.e. the checker treats the directive name after . in an asm block as a type identifier. V1 accepted this; vlib/v/slow_tests/assembly/asm_test.amd64.v:174 uses exactly this directive and currently only compiles through the V1 fallback.

Reproduction Steps

fn main() {
	mut a := int(0)
	asm amd64 {
		mov a, [rip + byte_sequence]
		; =r (a)
	}
	assert a == 0x480f3527
	println('ok')
}

asm amd64 {
	.global byte_sequence
	byte_sequence:
	.byte 0x27, 0x35, 0x0f, 0x48
}

v run byte_directive.v

The same block with .long 0x480f3527 instead of .byte ... gets past the checker (and then hits #28738, the top-level asm block not being emitted).

Expected Behavior

.byte is an assembler directive (like .global, .long, .quad); the deprecated-type check must not apply to tokens inside an asm block.

Current Behavior

byte_directive.v:14:3: error: byte is deprecated, use u8 instead
   12 |     .global byte_sequence
   13 |     byte_sequence:
   14 |     .byte 0x27, 0x35, 0x0f, 0x48
      |      ~~~~

Possible Solution

Skip the deprecated-byte type check for identifiers that are part of an asm block (directive names, labels, register names).

Additional Information/Context

Found while checking why vlib/v/slow_tests/assembly/asm_test.amd64.v fails under V3 (it passes in CI only via the V 0.5.2 fallback). Related: #28736 (arch-qualified test files), #28738 (top-level asm block dropped).

V version

V 0.5.2 01a8af9 (master, 2026-09-18)

Environment details

Windows 11 amd64, -cc gcc (mingw64 16.2); V3 compiler.