Selection/offsets incorrect when cgo is used

[joverbey]

When a file includes cgo code, the Go Doctor appears to map the user's selection to a completely incorrect AST node. This is because tokens' reported offsets do not correspond to the actual locations of the tokens in the original source file (probably due to cgo preprocessing). Tokens' line/column information is correct--it does match the original locations in the file--but the offsets appear to be quite different.

[joverbey]

A different issue (for Extract Function) had these two examples of problems from sqlite3 -- haven't checked, but sounds like this same issue (?):

db.go -- extraction has problem with position in cgo files
merge_operator.go -- try to rename a C.char parameter