Remove .gitignore entries not relevant in the monorepo.

Differential Revision: https://reviews.llvm.org/D100049

clang/.gitignore

@@ -26,13 +26,9 @@ cscope.out
 #==============================================================================#
 # Directories to ignore (do not add trailing '/'s, they skip symlinks).
 #==============================================================================#
-# Clang extra user tools, which is tracked independently (clang-tools-extra).
-tools/extra
 # Sphinx build products
 docs/_build
 docs/analyzer/_build
-# debug info testsuite
-test/debuginfo-tests
 
 # VS2017 and VSCode config files.
 .vscode

llvm/.gitignore

@@ -44,16 +44,6 @@ projects/*
 !projects/Makefile
 runtimes/*
 !runtimes/*.*
-# Clang, which is tracked independently.
-tools/clang
-# LLDB, which is tracked independently.
-tools/lldb
-# lld, which is tracked independently.
-tools/lld
-# Polly, which is tracked independently.
-tools/polly
-# avrlit, which is tracked independently.
-tools/avrlit
 # Sphinx build tree, if building in-source dir.
 docs/_build
 # VS2017 and VSCode config files.