Add an explicit toggle for the static analyzer in clang-tidy

Instead of using CLANG_ENABLE_STATIC_ANALYZER for use of the
static analyzer in both clang and clang-tidy, add a second
toggle CLANG_TIDY_ENABLE_STATIC_ANALYZER.

This allows enabling the static analyzer in clang-tidy while
disabling it in clang.

Differential Revison: https://reviews.llvm.org/D87118
diff --git a/clang/CMakeLists.txt b/clang/CMakeLists.txt
index f015951..3db476c 100644
--- a/clang/CMakeLists.txt
+++ b/clang/CMakeLists.txt
@@ -473,7 +473,8 @@
   "Build the Clang tools. If OFF, just generate build targets." ON)
 
 option(CLANG_ENABLE_ARCMT "Build ARCMT." ON)
-option(CLANG_ENABLE_STATIC_ANALYZER "Build static analyzer." ON)
+option(CLANG_ENABLE_STATIC_ANALYZER
+  "Include static analyzer in clang binary." ON)
 
 option(CLANG_ENABLE_PROTO_FUZZER "Build Clang protobuf fuzzer." OFF)