go/types: correct misspelling in function doc

The indirectType function comment uses the phrase 'layed out'. In the
context of that phrase, where something is being placed or sprawled,
the word should be 'laid'. 'Layed' is a misspelling of 'laid'.

Change-Id: I05ecb97637276e2252c47e92a0bd678130714889
GitHub-Last-Rev: 6ee67371b42c12ceaf4c6c245319748008ac7e7b
GitHub-Pull-Request: golang/go#27444
Reviewed-on: https://go-review.googlesource.com/132779


Reviewed-by: Ian Lance Taylor <iant@golang.org>