[llvm-pdbutil] Add support for dumping detailed module stats.

This adds support for dumping a summary of module symbols
and CodeView debug chunks.  This option prints a table for
each module of all of the symbols that occurred in the module
and the number of times it occurred and total byte size.  Then
at the end it prints the totals for the entire file.

Additionally, this patch adds the -jmc (just my code) option,
which suppresses modules which are from external libraries or
linker imports, so that you can focus only on the object files
and libraries that originate from your own source code.

llvm-svn: 311338