[docs] Clean up some more llvm-gcc stuff

Some references to llvm-gcc were so crusty that I wasn't sure how to
proceed and so I've left them intact.

I also slipped in a quick peephole fix to use a :doc: link instead of
raw HTML link.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201619 91177308-0d34-0410-b5e6-96231b3b80d8

docs/tutorial/LangImpl7.rst

@@ -237,7 +237,7 @@ strongly recommend that you use this technique for building SSA form,
 unless there is an extremely good reason not to. Using this technique
 is:
 
--  Proven and well tested: llvm-gcc and clang both use this technique
+-  Proven and well tested: clang uses this technique
    for local mutable variables. As such, the most common clients of LLVM
    are using this to handle a bulk of their variables. You can be sure
    that bugs are found fast and fixed early.

docs/tutorial/LangImpl8.rst

@@ -72,7 +72,7 @@ For example, try adding:
    info <../SourceLevelDebugging.html>`_ which is understood by common
    debuggers like GDB. Adding support for debug info is fairly
    straightforward. The best way to understand it is to compile some
-   C/C++ code with "``llvm-gcc -g -O0``" and taking a look at what it
+   C/C++ code with "``clang -g -O0``" and taking a look at what it
    produces.
 -  **exception handling support** - LLVM supports generation of `zero
    cost exceptions <../ExceptionHandling.html>`_ which interoperate with

docs/tutorial/OCamlLangImpl7.rst

@@ -237,7 +237,7 @@ strongly recommend that you use this technique for building SSA form,
 unless there is an extremely good reason not to. Using this technique
 is:
 
--  Proven and well tested: llvm-gcc and clang both use this technique
+-  Proven and well tested: clang uses this technique
    for local mutable variables. As such, the most common clients of LLVM
    are using this to handle a bulk of their variables. You can be sure
    that bugs are found fast and fixed early.

docs/tutorial/OCamlLangImpl8.rst

@@ -72,7 +72,7 @@ For example, try adding:
    info <../SourceLevelDebugging.html>`_ which is understood by common
    debuggers like GDB. Adding support for debug info is fairly
    straightforward. The best way to understand it is to compile some
-   C/C++ code with "``llvm-gcc -g -O0``" and taking a look at what it
+   C/C++ code with "``clang -g -O0``" and taking a look at what it
    produces.
 -  **exception handling support** - LLVM supports generation of `zero
    cost exceptions <../ExceptionHandling.html>`_ which interoperate with