gotest: use a space rather than a middle dot in target lists
gotest: use a space rather than a middle dot in target lists

Replace the U+00B7 middle dot character, placed after "mips64p32le"
in the target lists, with a space.  The U+00B7 character may not be
considered whitespace by Bourne shell and any non-ASCII character
may render incorrectly in some terminal devices.

Change-Id: Ibcf3c4ea8d7e86022e9b323b8d770f4b4c8be80c
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/251177
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

golang/gofrontend,golang/gofrontend,golang/gofrontend,golang/gofrontend