Fixes symbol resolution for a function with a tail call because the PC

for the frame is one past the address range of the calling function.
- Lowers the fix from RegisterContextLLDB for use with disassembly
- Fixes one of three issues in the disassembly test in TestInferiorAssert.py

Also adds documentation that explains the resolution depths and interface.

Note: This change affects the resolution scope for eSymbolContextFunction
without impacting the performance of eSymbolContextSymbol.

Thanks to Matt Kopec for his review.

llvm-svn: 190812