Rollup merge of #127434 - onur-ozkan:use-bootstrap-instead-of-rustbuild, r=Mark-Simulacrum

use "bootstrap" instead of "rustbuild" in comments and docs

Let's stick with the single name "bootstrap" to refer to the bootstrap project to avoid confusion. This should make it clearer, especially for new contributors.

compiler/rustc_session/src/config.rs

@@ -2620,7 +2620,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         // This is the location used by the `rust-src` `rustup` component.
         let mut candidate = sysroot.join("lib/rustlib/src/rust");
         if let Ok(metadata) = candidate.symlink_metadata() {
-            // Replace the symlink rustbuild creates, with its destination.
+            // Replace the symlink bootstrap creates, with its destination.
             // We could try to use `fs::canonicalize` instead, but that might
             // produce unnecessarily verbose path.
             if metadata.file_type().is_symlink() {