Add large-workspace stress test benchmark

Author: Kobzol

collector/compile-benchmarks/README.md

@@ -86,6 +86,8 @@ compiler in interesting ways.
 - **issue-88862**: A MCVE of a program that had a
   [severe performance regression](https://github.com/rust-lang/rust/issues/88862)
   when trying to normalize large opaque types with late-bound regions.
+- **large-workspace**: A stress test for searching for and loading metadata of a
+  large number (500) of dependent crates, and instantiating generic/inlined code from them.
 - **many-assoc-items**: Contains a struct with many associated items, which
   caused [quadratic behavior](https://github.com/rust-lang/rust/issues/68957)
   in the past.

collector/compile-benchmarks/REUSE.toml

@@ -150,6 +150,11 @@ path = "issue-88862/**"
 SPDX-FileCopyrightText = "The Rust Project Developers (see https://thanks.rust-lang.org)"
 SPDX-License-Identifier = "MIT"
 
+[[annotations]]
+path = "large-workspace/**"
+SPDX-FileCopyrightText = "The Rust Project Developers (see https://thanks.rust-lang.org)"
+SPDX-License-Identifier = "MIT"
+
 [[annotations]]
 path = "libc-0.2.172/**"
 SPDX-FileCopyrightText = "The Rust Project Developers (see https://thanks.rust-lang.org)"

collector/compile-benchmarks/large-workspace/0-println.patch

@@ -0,0 +1,13 @@
+diff --git a/src/main.rs b/src/main.rs
+index 801d39e1..b0c76e19 100644
+--- a/src/main.rs
++++ b/src/main.rs
+@@ -46,7 +46,7 @@ fn main() {
+     dep14::code_generic(1u32);
+     dep15::code();
+     dep15::code_inlined();
+-    dep15::code_generic(1u32);
++    dep15::code_generic(2u32);
+     dep16::code();
+     dep16::code_inlined();
+     dep16::code_generic(1u32);