Added new options to memory read to allow saving memory to disk

as binary bytes or as an ASCII text dump. 
- The output file is specified with the  "--outfile FILE" option.
- The memory can be appended to an existing file using the "--append" option. 
- The memory will be written as an ASCII text dump by default, or as 
  binary with the "--binary" option. 

Added new options to memory write to allow writing all or part of
a file on disk to target memory:
- The input file is specified using the "--infile FILE" option
- The offset at which to start in the file defaults to zero, but
  can be overridden using the "--offset OFFSET" option. If the
  size is not specified, the remaining number of bytes in the file
  will be used as the default byte size.
- The number of bytes to write defaults to the entire file byte
  size, but can be changed with the "--size COUNT" option.
 

llvm-svn: 116172