Ignore compile_commands.json only at the root of the tree.

Can avoid a problem if tools/clang/tools/extra is in the tree.

Patch by Douglas Yung!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233307 91177308-0d34-0410-b5e6-96231b3b80d8

.gitignore

@@ -37,7 +37,7 @@ cscope.files
 cscope.out
 autoconf/aclocal.m4
 autoconf/autom4te.cache
-compile_commands.json
+/compile_commands.json
 
 #==============================================================================#
 # Directories to ignore (do not add trailing '/'s, they skip symlinks).