rustbuild: Fix MSBuild location of `llvm-config.exe`

For LLD integration the path to `llvm-config` needed to change to inside the
build directory itself (for whatever reason) but the build directory is
different on MSBuild than it is on `ninja` for MSVC builds, so the path to
`llvm-config.exe` was actually wrong and not working!

This commit removes the `Build::llvm_config` function in favor of the source of
truth, the `Llvm` build step itself. The build step was then updated to find the
right build directory for MSBuild as well as `ninja` for where `llvm-config.exe`
is located.

Closes #48749

1 files changed, 1 insertions, 1 deletions

diff --git a/src/bootstrap/doc.rs b/src/bootstrap/doc.rs
index a791dd13f0f..5bc582b3507 100644
--- a/src/bootstrap/doc.rs
+++ b/src/bootstrap/doc.rs
@@ -481,7 +481,7 @@ impl Step for Std {
         t!(symlink_dir_force(&my_out, &out_dir));
 
         let mut cargo = builder.cargo(compiler, Mode::Libstd, target, "doc");
-        compile::std_cargo(build, &compiler, target, &mut cargo);
+        compile::std_cargo(builder, &compiler, target, &mut cargo);
 
         // We don't want to build docs for internal std dependencies unless
         // in compiler-docs mode. When not in that mode, we whitelist the crates