x/website: doc/install/gccgo is not up to date

[perillo]

https://golang.org/doc/install/gccgo does not list GCC 10 and GCC 11.

[mknyszek]

CC @ianlancetaylor via https://dev.golang.org/owners Is that correct? Does anything need to be updated on that page?

[gopherbot]

Change https://golang.org/cl/323130 mentions this issue: doc/install/gccgo: update for GCC 10 and 11

[perillo]

I have also noted that, starting from GCC 10, Go is no longer listed in the New Languages and Language specific improvements section.

Finally, for convenience, I would like to report a typo in the gccgo documentation. In https://gcc.gnu.org/onlinedocs/gcc-11.1.0/gccgo/Function-Names.html#Function-Names, an AMPERSAND character was escaped:
i := c_open(&name[0], os.O_RDONLY, 0);

[ianlancetaylor]

@perillo Thanks. I fixed those problems in the GCC repos.