commit c89c03b58becb12c6343a06788a28ea386fe4430
author David Blaikie <dblaikie@gmail.com> Mon Dec 17 08:27:19 2018 +0000
committer David Blaikie <dblaikie@gmail.com> Mon Dec 17 08:27:19 2018 +0000
tree c0da21d3398cf9e4d467dab4327d0e93d204792d
parent 8178ac881e1073067643abe6126306dfc7ec24ff

DebugInfo: Assume an absence of ranges or high_pc on a CU means the CU is empty (devoid of code addresses)

GCC emitted these unconditionally on/before 4.4/March 2012
Clang emitted these unconditionally on/before 3.5/March 2014

This improves performance when parsing CUs (especially those using split
DWARF) that contain no code ranges (such as the mini CUs that may be
created by ThinLTO importing - though generally they should be/are
avoided, especially for Split DWARF because it produces a lot of very
small CUs, which don't scale well in a bunch of other ways too
(including size)).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349333 91177308-0d34-0410-b5e6-96231b3b80d8