[docs] Rename 22 popular LLVM docs .rst -> .md (#201243)

Tracking issue: #201242
RFC: https://discourse.llvm.org/t/rfc-make-myst-markdown-the-llvm-docs-format-rip-rest/90840
Migration guide: https://llvm.org/docs/SphinxQuickstartTemplate.html#markdown-migration-guidelines

Update filename references, but leave the docs with reST syntax to
ensure rename detection works.

This intentionally breaks the documentation build, but I will immediately follow up by merging the PR that fixes it.

llvm/README.txt

@@ -9,7 +9,7 @@ LLVM is open source software. You may freely distribute it under the terms of
 the license agreement found in LICENSE.txt.
 
 Please see the documentation provided in docs/ for further
-assistance with LLVM, and in particular docs/GettingStarted.rst for getting
+assistance with LLVM, and in particular docs/GettingStarted.md for getting
 started with LLVM and docs/README.txt for an overview of LLVM's
 documentation setup.
 

llvm/docs/GitRepositoryPolicy.md

@@ -22,7 +22,7 @@ Requirements for *new* repositories as part of the
 
 If you want to integrate your project as part of the Monorepo, please take a
 look at the
-[Developer Policy](project:DeveloperPolicy.rst#Adding an Established Project To the LLVM Monorepo).
+[Developer Policy](project:DeveloperPolicy.md#Adding an Established Project To the LLVM Monorepo).
 
 To request a new repository, please create an issue with in
 [LLVM's Github Issue Tracker](https://github.com/llvm/llvm-project/issues) and

llvm/docs/InstrRefDebugInfo.md

@@ -191,4 +191,4 @@ instruction number of any cloned instruction, to avoid duplicate numbers
 appearing to `LiveDebugValues`. Dealing with duplicated instructions is a
 natural extension to instruction referencing that's currently unimplemented.
 
-[LiveDebugValues]: project:SourceLevelDebugging.rst#LiveDebugValues expansion of variable locations
+[LiveDebugValues]: project:SourceLevelDebugging.md#LiveDebugValues expansion of variable locations

llvm/docs/RemoveDIsDebugInfo.md

@@ -206,7 +206,7 @@ Below is a brief overview of the new representation that replaces debug intrinsi
 
 ### What exactly have you replaced debug intrinsics with?
 
-We're using a dedicated C++ class called `DbgRecord` to store debug info, with a one-to-one relationship between each instance of a debug intrinsic and each `DbgRecord` object in any LLVM IR program; these `DbgRecord`s are represented in the IR as non-instruction debug records, as described in the [Source Level Debugging](project:SourceLevelDebugging.rst#Debug Records) document. This class has a set of subclasses that store exactly the same information as is stored in debugging intrinsics. Each one also has almost entirely the same set of methods, that behave in the same way:
+We're using a dedicated C++ class called `DbgRecord` to store debug info, with a one-to-one relationship between each instance of a debug intrinsic and each `DbgRecord` object in any LLVM IR program; these `DbgRecord`s are represented in the IR as non-instruction debug records, as described in the [Source Level Debugging](project:SourceLevelDebugging.md#Debug Records) document. This class has a set of subclasses that store exactly the same information as is stored in debugging intrinsics. Each one also has almost entirely the same set of methods, that behave in the same way:
 
   https://llvm.org/docs/doxygen/classllvm_1_1DbgRecord.html
   https://llvm.org/docs/doxygen/classllvm_1_1DbgVariableRecord.html

llvm/docs/SphinxQuickstartTemplate.md

@@ -23,7 +23,7 @@ See the {ref}`migration <markdown_migration_guidelines>` section for more inform
 
 This article is located in `docs/SphinxQuickstartTemplate.md`.
 To use it as a template, make a copy and open it in a text editor.
-You can then write your docs, and open a [GitHub PR](project:GitHub.rst) to request a review.
+You can then write your docs, and open a [GitHub PR](project:GitHub.md) to request a review.
 
 To view the Markdown source file for this article, click **Show Source** on the right sidebar.
 
@@ -167,7 +167,7 @@ without any syntax highlighting like this:
 
 You can generate the HTML documentation from the sources locally if you want to
 see what they would look like. In addition to the normal
-[build tools](project:GettingStarted.rst)
+[build tools](project:GettingStarted.md)
 you need to install [Sphinx] and the necessary extensions
 using the following command inside the `llvm-project` checkout:
 

llvm/docs/conf.py

@@ -292,7 +292,7 @@ def process_rst(name):
 
 for name in os.listdir(command_guide_path):
     # Process Markdown files
-    if name.endswith(".md"):
+    if name.endswith(".md") and name != "index.md":
         process_md(name)
     # Process ReST files apart from the index page.
     elif name.endswith(".rst") and name != "index.rst":

llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp

@@ -57,7 +57,7 @@ Error AppleAcceleratorTable::extract() {
   FormParams = {Hdr.Version, 0, dwarf::DwarfFormat::DWARF32};
 
   // Check that we can read all the hashes and offsets from the
-  // section (see SourceLevelDebugging.rst for the structure of the index).
+  // section (see SourceLevelDebugging.md for the structure of the index).
   if (!AccelSection.isValidOffset(getIthBucketBase(Hdr.BucketCount - 1)))
     return createStringError(
         errc::illegal_byte_sequence,

llvm/lib/IR/DebugInfo.cpp

@@ -2381,7 +2381,7 @@ bool AssignmentTrackingPass::runOnFunction(Function &F) {
   // Note: trackAssignments doesn't respect dbg.declare's IR positions (as it
   // doesn't "understand" dbg.declares). However, this doesn't appear to break
   // any rules given this description of dbg.declare from
-  // llvm/docs/SourceLevelDebugging.rst:
+  // llvm/docs/SourceLevelDebugging.md:
   //
   //   It is not control-dependent, meaning that if a call to llvm.dbg.declare
   //   exists and has a valid location argument, that address is considered to

llvm/tools/reduce-chunk-list/reduce-chunk-list.cpp

@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// See the llvm-project/llvm/docs/ProgrammersManual.rst to see how to use this
+// See the llvm-project/llvm/docs/ProgrammersManual.md to see how to use this
 // tool
 //
 //===----------------------------------------------------------------------===//

llvm/utils/lit/tests/Inputs/shtest-define/examples/param-subst.txt

@@ -1,4 +1,4 @@
-; This example originally appeared in TestingGuide.rst except here we've added
+; This example originally appeared in TestingGuide.md except here we've added
 ; echo to the clang/FileCheck command line to be executed.
 
 ; DEFINE: %{cflags} =