Auto merge of #50336 - japaric:llvm-tools, r=Mark-Simulacrum

ship LLVM tools with the toolchain

this PR adds llvm-{nm,objcopy,objdump,size} to the rustc sysroot (right next to LLD)

this slightly increases the size of the rustc component. I measured these numbers on x86_64 Linux:

- rustc-1.27.0-dev-x86_64-unknown-linux-gnu.tar.gz 180M -> 193M (+7%)
- rustc-1.27.0-dev-x86_64-unknown-linux-gnu.tar.xz 129M -> 137M (+6%)

r? @alexcrichton
cc #49584

src/bootstrap/configure.py

@@ -335,6 +335,7 @@ for key in known_args:
     elif option.name == 'full-tools':
         set('rust.codegen-backends', ['llvm', 'emscripten'])
         set('rust.lld', True)
+        set('rust.llvm-tools', True)
         set('build.extended', True)
     elif option.name == 'option-checking':
         # this was handled above