tools/clang/declextract: move from tools/syz-declextract/clangtool

Some of the common helpers may be reused across different Clang tools
(currently json.h and .clang-format). Move the files to allow such reuse.

Author: dvyukov

Makefile

@@ -272,7 +272,8 @@ format_cpp:
 	clang-format --style=file -i executor/*.cc executor/*.h \
 		executor/android/android_seccomp.h \
 		tools/kcovtrace/*.c tools/kcovfuzzer/*.c tools/fops_probe/*.cc \
-		tools/syz-declextract/clangtool/*.cpp tools/syz-declextract/clangtool/*.h
+		tools/clang/*.h \
+		tools/clang/declextract/*.h tools/clang/declextract/*.cpp
 
 format_sys: bin/syz-fmt
 	bin/syz-fmt all

…/syz-declextract/clangtool/.clang-format tools/clang/.clang-formattools/syz-declextract/clangtool/.clang-format renamed to tools/clang/.clang-format tools/syz-declextract/clangtool/.clang-format renamed to tools/clang/.clang-format

@@ -29,7 +29,7 @@ target_link_libraries(syz-declextract PRIVATE clangTooling)
 ```
 mkdir $LLVM/clang/syz-declextract
 ```
-Copy `tools/syz-declextract/clangtool/*.{cpp,h}` files to `$LLVM/clang/syz-declextract/` directory.
+Copy `tools/clang/declextract/*.{cpp,h}` and `tools/clang/*.h` files to `$LLVM/clang/syz-declextract/` directory.
 ```
 LLVM_BUILD=$PWD/syz
 mkdir $LLVM_BUILD && cd $LLVM_BUILD