Refactor spirv-builder to build codegen and sysroot itself

crates/spirv-builder/Cargo.toml

@@ -5,20 +5,18 @@ authors = ["Embark <[email protected]>"]
 edition = "2018"
 license = "MIT OR Apache-2.0"
 
-# See rustc_codegen_spirv/Cargo.toml for details on these features
-[features]
-default = ["use-compiled-tools"]
-use-installed-tools = ["rustc_codegen_spirv/use-installed-tools"]
-use-compiled-tools = ["rustc_codegen_spirv/use-compiled-tools"]
-
 [dependencies]
 memchr = "2.3"
 raw-string = "0.3.5"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-# See comment in lib.rs invoke_rustc for why this is here
-rustc_codegen_spirv = { path = "../rustc_codegen_spirv", default-features = false }
+# TODO: Update before merge.
+cargo-sysroot = { git = "https://github.com/XAMPPRocky/cargo-sysroot", branch = "main" }
+git2 = "0.13.12"
+eyre = "0.6.2"
+remove_dir_all = "0.6.1"
 
 [dev-dependencies]
 lazy_static = "1.4"
 pretty_assertions = "0.6"
+rspirv = { git = "https://github.com/gfx-rs/rspirv.git", rev = "f11f8797bd4df2d1d22cf10767b39a5119c57551" }

crates/spirv-builder/build.rs

@@ -0,0 +1,3 @@
+/// Empty build script to force cargo to generate an empty `OUT_DIR` directory
+/// that we can use as a scratchpad directory for tests.
+fn main() {}