Generate PDB files for profiling even in Release build.
Generate PDB files for profiling even in Release build.

This patch enables PDB generation for Release build, which has
slightly different optimize option with RelWithDebInfo on windows.

This helps to know slow part of Release build when profiling.

Patch by Takuto Ikuta
Differential Revision: https://reviews.llvm.org/D42632

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@324504 91177308-0d34-0410-b5e6-96231b3b80d8

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