[lldb] [gdb-remote] Fix processing generic regnums

Fix regression in processing generic regnums that was introduced
in fa45650 ("[lldb] [gdb-remote]
Refactor getting remote regs to use local vector").  Since then,
the "generic" field was wrongly interpreted as integer rather than
string constant.

Thanks to Ted Woodward for noticing and providing the correct code.

lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp

@@ -492,7 +492,7 @@ void ProcessGDBRemote::BuildDynamicRegisterInfo(bool force) {
           } else if (name.equals("dwarf")) {
             value.getAsInteger(0, reg_info.regnum_dwarf);
           } else if (name.equals("generic")) {
-            value.getAsInteger(0, reg_info.regnum_generic);
+            reg_info.regnum_generic = Args::StringToGenericRegister(value);
           } else if (name.equals("container-regs")) {
             SplitCommaSeparatedRegisterNumberString(value, reg_info.value_regs, 16);
           } else if (name.equals("invalidate-regs")) {