Grab the latest, greatest config from bevy upstream

.cargo/config.fast

@@ -1,3 +1,5 @@
+# Rename this file to `config.toml` to enable "fast build" configuration. Please read the notes below.
+
 # NOTE: For maximum performance, build using a nightly compiler
 # If you are using rust stable, remove the "-Zshare-generics=y" below.
 
@@ -8,8 +10,13 @@ rustflags = ["-Clink-arg=-fuse-ld=lld", "-Zshare-generics=y"]
 # NOTE: you must manually install https://github.com/michaeleisel/zld on mac. you can easily do this with the "brew" package manager:
 # `brew install michaeleisel/zld/zld`
 [target.x86_64-apple-darwin]
-rustflags = ["-C", "link-arg=-fuse-ld=/usr/local/bin/zld", "-Zshare-generics=y"]
+rustflags = ["-C", "link-arg=-fuse-ld=/usr/local/bin/zld", "-Zshare-generics=y", "-Zrun-dsymutil=no"]
 
 [target.x86_64-pc-windows-msvc]
 linker = "rust-lld.exe"
-rustflags = ["-Zshare-generics=y"]
+rustflags = ["-Zshare-generics=y"]
+
+# Optional: Uncommenting the following improves compile times, but reduces the amount of debug info to 'line number tables only'
+# In most cases the gains are negligible, but if you are on macos and have slow compile times you should see significant gains.
+#[profile.dev]
+#debug = 1