Emit line numbers in CodeView for trailing (after `ret`) blocks from inlined functions

Issue Details:
When building up line information for CodeView debug info, LLVM attempts to gather the "range" of instructions within a function as these are printed together in a single record. If there is an inlined function, then those lines are attributed to the original function to enable generating `S_INLINESITE` records. However, this thus requires there to be instructions from the inlining function after the inlined function otherwise the instruction range would not include the inlined function.

Fix Details:
Include any inlined functions when finding the extent of a function in `getFunctionLineEntries`

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D159226