llvm-xray: Broken chrome trace event format output
llvm-xray: Broken chrome trace event format output

Summary:
Missing comma separator for EXIT and TAIL_EXIT RecordTypes emit invalid
JSON output for Chrome Trace Event Format.

Reviewers: dberris

Reviewed By: dberris

Subscribers: sammccall, kpw, llvm-commits

Differential Revision: https://reviews.llvm.org/D49687

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@337795 91177308-0d34-0410-b5e6-96231b3b80d8

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