[LLVMContext] Detecting leaked instructions with metadata
[LLVMContext] Detecting leaked instructions with metadata

When instructions with metadata are accidentally leaked, the result is a
difficult-to-find memory corruption in ~LLVMContextImpl that leads to
random crashes.

Patch by Arvīds Kokins!

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@336010 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm