[LLDB][NFC][Reliability] Fix uninitialized variables from Coverity scan. Part 3

Improve LLDB reliability by fixing the following "uninitialized variables" static code inspection warnings from
scan.coverity.com/projects/llvm:

1355854, 1347549, 1316348, 1372028, 1431625,
1315634, 1315637, 1355855, 1364803, 1420505,
1420563, 1420685, 1366014, 1203966, 1204029,
1204031, 1204032, 1328411, 1325969, 1325968,
1374921, 1094809

Differential Revision: https://reviews.llvm.org/D130602