[WebAssembly] Define a custom segment type for function definitions.
[WebAssembly] Define a custom segment type for function definitions.

Since function definitions are not loaded into the address space, PT_LOAD is
inappropriate. PT_WEBASSEMBLY_FUNCTIONS is used to identify where the function
definitions are so that they can be processed at program startup time.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@257436 91177308-0d34-0410-b5e6-96231b3b80d8

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