[ThinLTO] Internalize readonly globals

An attempt to recommit r346584 after failure on OSX build bot.
Fixed cache key computation in ThinLTOCodeGenerator and added
test case

llvm-svn: 347033

1 files changed, 0 insertions, 5 deletions

diff --git a/llvm/lib/Linker/IRMover.cpp b/llvm/lib/Linker/IRMover.cpp
index b304bfc401a..72e20ae0ba1 100644
--- a/llvm/lib/Linker/IRMover.cpp
+++ b/llvm/lib/Linker/IRMover.cpp
@@ -1062,11 +1062,6 @@ void IRLinker::prepareCompileUnitsForImport() {
     ValueMap.MD()[CU->getRawEnumTypes()].reset(nullptr);
     ValueMap.MD()[CU->getRawMacros()].reset(nullptr);
     ValueMap.MD()[CU->getRawRetainedTypes()].reset(nullptr);
-    // We import global variables only temporarily in order for instcombine
-    // and globalopt to perform constant folding and static constructor
-    // evaluation. After that elim-avail-extern will covert imported globals
-    // back to declarations, so we don't need debug info for them.
-    ValueMap.MD()[CU->getRawGlobalVariables()].reset(nullptr);
 
     // Imported entities only need to be mapped in if they have local
     // scope, as those might correspond to an imported entity inside a