minor fixes

Author: tshepang

src/doc/rustc-dev-guide/src/building/how-to-build-and-run.md

@@ -236,7 +236,7 @@ involve proc macros or build scripts, you must be sure to explicitly build targe
 host platform (in this case, `x86_64-unknown-linux-gnu`).
 
 If you want to always build for other targets without needing to pass flags to `x.py build`,
-then you can configure this in the `[build]` section of your `config.toml` like so:
+you can configure this in the `[build]` section of your `config.toml` like so:
 
 ```toml
 [build]

src/doc/rustc-dev-guide/src/debugging-support-in-rustc.md

@@ -125,14 +125,16 @@ visualization to serve up in the debugger.
 Both WinDbg and CDB support defining and viewing custom visualizations for any given type
 within the debugger using the Natvis framework. The Rust compiler defines a set of Natvis
 files that define custom visualizations for a subset of types in the standard libraries such
-as, `std, core and alloc`. These Natvis files are embedded into `PDBs` generated by the
+as, `std`, `core`, and `alloc`. These Natvis files are embedded into `PDBs` generated by the
 `*-pc-windows-msvc` target triples to automatically enable these custom visualizations when
 debugging. This default can be overridden by setting the `strip` rustc flag to either `debuginfo`
 or `symbols`.
 
 Rust has support for embedding Natvis files for crates outside of the standard libraries by
-using the `#[debugger_visualizer]` attribute. For more details on how to embed debugger visualizers
-please refer to the `#[debugger_visualizer]` attribute in [the unstable book](https://doc.rust-lang.org/unstable-book/language-features/debugger-visualizer.html).
+using the `#[debugger_visualizer]` attribute.
+For more details on how to embed debugger visualizers,
+please refer to the `#[debugger_visualizer]` attribute in
+[the unstable book](https://doc.rust-lang.org/unstable-book/language-features/debugger-visualizer.html).
 
 ## DWARF and `rustc`
 
@@ -349,4 +351,4 @@ but may have to add some mode to let the compiler understand some extensions.
 [PDB]: https://llvm.org/docs/PDB/index.html
 [symbol records]: https://llvm.org/docs/PDB/CodeViewSymbols.html
 [type records]: https://llvm.org/docs/PDB/CodeViewTypes.html
-[Windows Debugging Tools]: https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/
+[Windows Debugging Tools]: https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/