XML register info fix

There are a couple of bugs in the XML register info handling which this patch fixes:

+ conflicting variable names in lambda, both capture list and parameters contains a variable called 'name'.

+ prev_reg_num, which sets the register number, should be incremented after each register is processed.

+ Windows errors regarding empty strings and the 'xi:' prefix disappearing from 'xi:include' node name.

Reviewers: clayborg

Subscribers: lldb-commits, deepak2427

Differential Revision: http://reviews.llvm.org/D10731

llvm-svn: 240768