Rename symbols for Go 1.6?

[klauspost]

It seems that including both this and the Go 1.6 crc32 (with the same code) creates a symbol conflict.

C:\Go\pkg\tool\windows_amd64\link.exe: running gcc failed: exit status 1
e:\temp\wintemp\go-link-561199559/go.o:(.text+0x242fd0): multiple definition of `rupoly'
e:\temp\wintemp\go-link-561199559/go.o:(.text+0x242fe0): first defined here
e:\temp\wintemp\go-link-561199559/go.o:(.text+0x2422b8): multiple definition of `r5'
e:\temp\wintemp\go-link-561199559/go.o:(.text+0x2422c0): first defined here
e:\temp\wintemp\go-link-561199559/go.o:(.text+0x242eb0): multiple definition of `r4r3'
e:\temp\wintemp\go-link-561199559/go.o:(.text+0x242ec0): first defined here
e:\temp\wintemp\go-link-561199559/go.o:(.text+0x242e90): multiple definition of `r2r1'
e:\temp\wintemp\go-link-561199559/go.o:(.text+0x242ea0): first defined here
collect2.exe: error: ld returned 1 exit status

We should probably rename our globals to avoid this collision.