[libTooling] Fix `getFileRangeForEdit` for inner nested template types (#87673)

When there is `>>` in source from the right brackets of a nested
template, the end location of the inner template points into a scratch
space with a single `>` token. This prevents the lexer from seeing the
`>>` token in the original source.

However, this causes the range to appear to be partially in a macro, and
is problematic if we are trying to avoid ranges with any macro
expansions.

This change detects these split tokens in token ranges, converting it to the
corresponding character range without the expansion.