cmd/asm: nil deref (2)

[dvyukov]

cmd/asm crashes on the following input:

TEXT$:0:(SB

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x4b0571]

goroutine 1 [running]:
cmd/internal/obj.Mconv(0xc82007d6b0, 0x0, 0x0)
    src/cmd/internal/obj/util.go:473 +0x661
cmd/internal/obj.Dconv(0x70ec40, 0xc82007d6b0, 0x0, 0x0)
    src/cmd/internal/obj/util.go:397 +0xc0c
cmd/asm/internal/asm.(*Parser).getConstantPseudo(0xc82007de70, 0x6095b8, 0x4, 0xc82007d6b0, 0x7)
    src/cmd/asm/internal/asm/asm.go:644 +0x93
cmd/asm/internal/asm.(*Parser).evalInteger(0xc82007de70, 0x6095b8, 0x4, 0xc82010c230, 0x2, 0x3, 0x0)
    src/cmd/asm/internal/asm/asm.go:79 +0x9e
cmd/asm/internal/asm.(*Parser).asmText(0xc82007de70, 0xc82010a0a0, 0x4, 0xc82007db28, 0x3, 0x3)
    src/cmd/asm/internal/asm/asm.go:112 +0x24c
cmd/asm/internal/asm.(*Parser).pseudo(0xc82007de70, 0xd, 0xc82010a0a0, 0x4, 0xc82007db28, 0x3, 0x3)
    src/cmd/asm/internal/asm/parse.go:217 +0x222
cmd/asm/internal/asm.(*Parser).line(0xc82007de70, 0xc820112060)
    src/cmd/asm/internal/asm/parse.go:185 +0x9ac
cmd/asm/internal/asm.(*Parser).Parse(0xc82007de70, 0xc820112060, 0xc820102120)
    src/cmd/asm/internal/asm/parse.go:86 +0x21
main.main()
    src/cmd/asm/main.go:59 +0xb85

go version devel +499c827 Thu Sep 3 03:02:17 2015 +0000 linux/amd64

[gopherbot]

CL https://golang.org/cl/14498 mentions this issue.