Fixed a hang which causes LLDB to enter an infinite

loop if "memory read" is run with the -t option and
the type name contains a keyword like "struct" that
isn't followed by a space.  Now if a keyword isn't
followed by a space we continue searching after it,
instead of at the beginning of the type name.

Also optimized the code to not call strlen() on
a fixed set of statically-declared constant strings.

llvm-svn: 160016