[CI] Update LLVM_VERSION to 21. (#565)

Author: haonanya1

.github/workflows/codeql.yml

@@ -10,7 +10,7 @@ permissions:
   contents: read
 
 env:
-  LLVM_VERSION: 20
+  LLVM_VERSION: 21
   LLVM_VERSION_MINOR: 0
 
 jobs:

.github/workflows/on-push-verification-out-of-tree.yml

@@ -9,7 +9,7 @@ permissions:
   contents: read
 
 env:
-  LLVM_VERSION: 20
+  LLVM_VERSION: 21
   LLVM_VERSION_MINOR: 0
 
 on:

.github/workflows/scheduled-verification.yml

@@ -34,7 +34,7 @@ jobs:
     name: Verify `ocl-open-${{ matrix.llvm_version }}` release branch
     strategy:
       matrix:
-        llvm_version: [ 14, 15, 16, 17, 18, 19 ]
+        llvm_version: [ 14, 15, 16, 17, 18, 19, 20 ]
     runs-on: ubuntu-22.04
     steps:
 

CMakeLists.txt

@@ -39,7 +39,7 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
     add_definitions(-DUSE_PREBUILT_LLVM)
 
     if(NOT PREFERRED_LLVM_VERSION)
-        set(PREFERRED_LLVM_VERSION "20.0")
+        set(PREFERRED_LLVM_VERSION "21.0")
     endif(NOT PREFERRED_LLVM_VERSION)
     message(STATUS "[OPENCL-CLANG] Looking for LLVM version ${PREFERRED_LLVM_VERSION}")
     find_package(LLVM ${PREFERRED_LLVM_VERSION} REQUIRED)

README.md

@@ -77,7 +77,7 @@ LLVM by using the `PREFERRED_LLVM_VERSION` cmake option:
 
 Example:
 ```bash
-cmake -DPREFERRED_LLVM_VERSION="20.0" ../opencl-clang
+cmake -DPREFERRED_LLVM_VERSION="21.0" ../opencl-clang
 ```
 
 ##### Custom LLVM installation