Incorrect inactive region when preprocessor directive is preceded by a comment

[Colengms]

The C/C++ Extension currently deals with inactive regions using a per-line granularity, but the IntelliSense engine provides inactive regions with line/column (offset) granularity. Trying to reduce that granularity to per-line results in some unusual scenario, such as:

Using this issue to track propagating the full granularity of the inactive region We're using createTextEditorDecorationType to render regions as inactive, which should support line/column granularity.

Various features check inactive regions to determine if operating within an active region or not, which makes this a non-trivial change.