Revert "DebugInfo: Loosen DILexicalBlock constructor"
Revert "DebugInfo: Loosen DILexicalBlock constructor"

This reverts commit r234222, while I look into bot failures [1].  I'll
recommit soon.

[1]: http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_check/7117/

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@234225 91177308-0d34-0410-b5e6-96231b3b80d8

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