Fix LLVM pointer element type
Fix LLVM pointer element type

llvm::PointerType::isValidElementType() checks that the pointee type is
not void. Use a byte pointer instead.

Bug: b/155148722
Change-Id: Ibf2fd23ce0a19a6947a6817f0b73753cfa170832
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/49568
Tested-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>
Reviewed-by: Ben Clayton <1f693eb7158dc33015048c09d6712f74dabddf79@google.com>
Kokoro-Result: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

bkaradzic/SwiftShader,bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,google/swiftshader,google/swiftshader