redo ./run-test.sh based on MIRI_REPLACE_LIBRS_IF_NOT_TEST

Author: RalfJung

Cargo.toml

@@ -1,12 +1,22 @@
+# We set up our own workspace that contains the library crates.
+# `./run-test.sh` makes the `library` folder a symlink to the right place.
+# (Somehow, directly building things from `rustlib/src` does not work...)
 [workspace]
 members = [
-  "core_miri_test",
-  "alloc_miri_test",
-  "std_miri_test",
+  "library/std",
+  "library/sysroot",
 ]
 
 exclude = [
   # stdarch has its own Cargo workspace
   "library/stdarch",
-  "rust-src-patched/library/stdarch",
+  # this is just a staging ground for CI
+  "rust-src-patched",
 ]
+
+[patch.crates-io]
+# See comments in `library/rustc-std-workspace-core/README.md` for what's going on
+# here
+rustc-std-workspace-core = { path = 'library/rustc-std-workspace-core' }
+rustc-std-workspace-alloc = { path = 'library/rustc-std-workspace-alloc' }
+rustc-std-workspace-std = { path = 'library/rustc-std-workspace-std' }

alloc_miri_test/Cargo.toml

@@ -85,9 +85,10 @@ std)
     echo "::endgroup::"
     ;;
 simd)
-    cd $MIRI_LIB_SRC/portable-simd
+    export CARGO_TARGET_DIR=$(pwd)/target
     export RUSTFLAGS="-Ainternal_features ${RUSTFLAGS:-}"
     export RUSTDOCFLAGS="-Ainternal_features ${RUSTDOCFLAGS:-}"
+    cd $MIRI_LIB_SRC/portable-simd
 
     echo "::group::Testing portable-simd"
     MIRIFLAGS="$DEFAULTFLAGS" \