37f30185 added CMake rules to copy the `OpenCLDebugInfo100.h` header out of a polluted build intermediate directory and into a separate include directory.

Add this include directory to the .vscode include paths so vscode can also find it.

All of this smell should go away once https://github.com/KhronosGroup/SPIRV-Headers/issues/137 is addressed.

Bug: b/145351270
Change-Id: I1a20e6f6b507e10c90fed38dd8a94d4b3ff590f7
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/40129Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>