[Bug go/93679] New: gccgo cannot bootstrap go1.14

[schwab@linux-m68k.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93679

            Bug ID: 93679
           Summary: gccgo cannot bootstrap go1.14
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: go
          Assignee: ian at airs dot com
          Reporter: schwab@linux-m68k.org
                CC: cmang at google dot com
  Target Milestone: ---

When trying to bootstrap go1.14 from the release-branch.go1.14 branch with
gccgo-10 I'm getting this error:

+ ./cmd/dist/dist bootstrap -a -v -d
Building Go toolchain1 using /usr.
bootstrap/cmd/internal/objabi
bootstrap/cmd/internal/src
bootstrap/cmd/internal/bio
bootstrap/sort
# bootstrap/sort
/home/abuild/rpmbuild/BUILD/go-1.14+git20200206.d898c7b544/src/sort/slice_go113.go:9:28:
error: import file 'internal/reflectlite' not found
    9 | import "internal/reflectlite"
      |                            ^
/home/abuild/rpmbuild/BUILD/go-1.14+git20200206.d898c7b544/src/sort/slice_go113.go:11:22:
error: reference to undefined name 'reflectlite'
   11 | var reflectValueOf = reflectlite.ValueOf
      |                      ^
/home/abuild/rpmbuild/BUILD/go-1.14+git20200206.d898c7b544/src/sort/slice_go113.go:12:22:
error: reference to undefined name 'reflectlite'
   12 | var reflectSwapper = reflectlite.Swapper
      |                      ^
/home/abuild/rpmbuild/BUILD/go-1.14+git20200206.d898c7b544/src/sort/slice.go:36:25:
error: increment or decrement of non-numeric type
   36 |  for i := n - 1; i > 0; i-- {
      |                         ^

Bootstrapping with gccgo-9 works without error.