Bump blink_gc_plugin version number to trigger redownload of the clang package again

tools/clang/blink_gc_plugin/CMakeLists.txt

 cmake_minimum_required(VERSION 2.8.8)
 project(BlinkGCPlugin)
 
 # This pugin is built using LLVM's build system, not Chromium's.
 # It expects LLVM_SRC_DIR and LLVM_BUILD_DIR to be set.
 # For example:
 #
 # cmake -GNinja \
 #   -DLLVM_BUILD_DIR=$CHROMIUM_SRC_DIR/third_party/llvm-build/Release+Asserts \
 #   -DLLVM_SRC_DIR=$CHROMIUM_SRC_DIR/third_party/llvm \
@@ skipping 19 matching lines @@
 set(LLVM_RUNTIME_OUTPUT_INTDIR "${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/bin")
 set(LLVM_LIBRARY_OUTPUT_INTDIR "${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib")
 
 include_directories("${LLVM_SRC_DIR}/include"
                     "${LLVM_SRC_DIR}/tools/clang/include"
                     "${LLVM_BUILD_DIR}/include"
                     "${LLVM_BUILD_DIR}/tools/clang/include")
 
 # This line is read by update.sh and other scripts in tools/clang/scripts
 # Note: The spaces are significant.
-set(LIBRARYNAME BlinkGCPlugin_11)
+set(LIBRARYNAME BlinkGCPlugin_12)
 
 add_llvm_loadable_module("lib${LIBRARYNAME}"
                          BlinkGCPlugin.cpp
                          Edge.cpp
                          RecordInfo.cpp
                         )