[libclc] Add Maintainers.md for libclc (#118309)

This adds a Maintainers.md files to libclc. Recently I needed to find a
libclc maintainer and I had no idea there was one listed in llvm/
instead of in libclc/.

Author: DavidSpickett

libclc/Maintainers.md

@@ -0,0 +1,17 @@
+# libclc Maintainers
+
+This file is a list of the
+[maintainers](https://llvm.org/docs/DeveloperPolicy.html#maintainers) for
+libclc.
+
+## Current Maintainers
+
+The following people are the active maintainers for the project. Please reach
+out to them for code reviews, questions about their area of expertise, or other
+assistance.
+
+Fraser Cormack \
+fraser@codeplay.com (email), [frasercrmck](https://github.com/frasercrmck) (GitHub)
+
+Tom Stellard \
+tstellar@redhat.com (email), [tstellar](https://github.com/tstellar) (GitHub)

llvm/Maintainers.md

@@ -414,7 +414,6 @@ gkistanova@gmail.com (email), [gkistanova](https://github.com/gkistanova) (GitHu
 ### Other subprojects
 
 Some subprojects maintain their own list of per-component maintainers.
-Others only have a lead maintainer listed here.
 
 [Bolt maintainers](https://github.com/llvm/llvm-project/blob/main/bolt/Maintainers.txt)
 
@@ -428,6 +427,8 @@ Others only have a lead maintainer listed here.
 
 [libc++ maintainers](https://github.com/llvm/llvm-project/blob/main/libcxx/Maintainers.md)
 
+[libclc maintainers](https://github.com/llvm/llvm-project/blob/main/libclc/Maintainers.md)
+
 [LLD maintainers](https://github.com/llvm/llvm-project/blob/main/lld/Maintainers.md)
 
 [LLDB maintainers](https://github.com/llvm/llvm-project/blob/main/lldb/Maintainers.rst)
@@ -436,11 +437,6 @@ Others only have a lead maintainer listed here.
 
 [Polly maintainers](https://github.com/llvm/llvm-project/blob/main/polly/Maintainers.md)
 
-#### libclc
-
-Tom Stellard \
-tstellar@redhat.com (email), [tstellar](https://github.com/tstellar) (GitHub)
-
 ## Inactive Maintainers
 
 The following people have graciously spent time performing maintainer