[llvm-debuginfo-analyzer] (05/09) - Select elements

The test case 'checkFlexiblePatterns' caused a failure in:

  https://lab.llvm.org/buildbot/#/builders/85/builds/11590
  SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior
    runtime error: applying zero offset to null pointer
    llvm/lib/Support/regengine.inc:151:18

The logical view is traversed and for each logical element a
series of match criterias are applied. One of those criterias
is to match its name or type name to a given pattern.

If the logical element does not have a type (for instance a
'namespace') do not try to use its type name, which is a
empty string as the 'matcher' function receives a null pointer.

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D136444