Add llvm-pdbutil tool_patterns in lit.cfg

[sbc100]

Summary

This means that 'llvm-pdbutil' in test commands will resolve
to the absolute path to the tool, in line with what happens
already for other tools.

This works either way because the bin directory is also
prepended to the PATH. I'm not sure why both methods are
used.

[sbc100]

sort

[sbc100]

I noticed this when debugging the recent pdb-none.test test failures.

[zturner]

Oh wait, I get it. This is for lld, not for llvm. Yea I made the same fix for llvm. lgtm

lld/trunk/test/lit.cfg

tool_patterns = [r"\bFileCheck\b",
                  r"\bnot\b",
                  NoPreJunk + r"\blld\b" + NoPostJunk,
                  r"\bld.lld\b",
                  r"\blld-link\b",
                  r"\bllvm-as\b",
                  r"\bllvm-mc\b",
                  r"\bllvm-nm\b",
                  r"\bllvm-objdump\b",
+                 r"\bllvm-pdbutil\b",
                  r"\bllvm-readobj\b",
                  r"\bobj2yaml\b",
                  r"\byaml2obj\b"]
 
 for pattern in tool_patterns:
     # Extract the tool name from the pattern.  This relies on the tool
     # name being surrounded by \b word match operators.  If the
     # pattern starts with "| ", include it in the string to be