fix links

Author: mark-i-m

src/building/how-to-build-and-run.md

@@ -256,7 +256,7 @@ in other sections:
   - `./x.py build --stage 1` – builds everything using the stage 1 compiler,
     not just up to libstd
   - `./x.py build` – builds the stage2 compiler
-- Running tests (see the [section on running tests](./tests/running.html) for
+- Running tests (see the [section on running tests](../tests/running.html) for
   more details):
   - `./x.py test --stage 1 src/libstd` – runs the `#[test]` tests from libstd
   - `./x.py test --stage 1 src/test/ui` – runs the `ui` test suite

src/building/suggested.md

@@ -53,7 +53,7 @@ the MIR).
 
 **The TL;DR is that you might get weird behavior from a compile when
 using `--keep-stage 1`** -- for example, strange
-[ICEs](appendix/glossary.html) or other panics. In that case, you
+[ICEs](../appendix/glossary.html) or other panics. In that case, you
 should simply remove the `--keep-stage 1` from the command and
 rebuild.  That ought to fix the problem.
 

src/profiling/with_perf.md

@@ -14,7 +14,7 @@ This is a guide for how to profile rustc with [perf](https://perf.wiki.kernel.or
 - Make a rustup toolchain pointing to that result
   - see [the "build and run" section for instructions][b-a-r]
 
-[b-a-r]: ../how-to-build-and-run.html#toolchain
+[b-a-r]: ../building/how-to-build-and-run.html#toolchain
 
 ## Gathering a perf profile