[build] Rename clang-headers to clang-resource-headers

Summary:
The current install-clang-headers target installs clang's resource
directory headers. This is different from the install-llvm-headers
target, which installs LLVM's API headers. We want to introduce the
corresponding target to clang, and the natural name for that new target
would be install-clang-headers. Rename the existing target to
install-clang-resource-headers to free up the install-clang-headers name
for the new target, following the discussion on cfe-dev [1].

I didn't find any bots on zorg referencing install-clang-headers. I'll
send out another PSA to cfe-dev to accompany this rename.

[1] http://lists.llvm.org/pipermail/cfe-dev/2019-February/061365.html

Reviewers: beanz, phosek, tstellar, rnk, dim, serge-sans-paille

Subscribers: mgorny, javed.absar, jdoerfert, #sanitizers, openmp-commits, lldb-commits, cfe-commits, llvm-commits

Tags: #clang, #sanitizers, #lldb, #openmp, #llvm

Differential Revision: https://reviews.llvm.org/D58791

llvm-svn: 355340
diff --git a/llvm/docs/Docker.rst b/llvm/docs/Docker.rst
index 7862c5a..5a42cbe 100644
--- a/llvm/docs/Docker.rst
+++ b/llvm/docs/Docker.rst
@@ -79,7 +79,7 @@
     ./llvm/utils/docker/build_docker_image.sh \
 	--source debian8 \
 	--docker-repository clang-debian8 --docker-tag "staging" \
-	-p clang -i install-clang -i install-clang-headers \
+	-p clang -i install-clang -i install-clang-resource-headers \
 	-- \
 	-DCMAKE_BUILD_TYPE=Release
 
@@ -95,11 +95,11 @@
     ./build_docker_image.sh \
 	--source debian8 \
 	--docker-repository clang-debian8 --docker-tag "staging" \
-	-p clang -i stage2-install-clang -i stage2-install-clang-headers \
+	-p clang -i stage2-install-clang -i stage2-install-clang-resource-headers \
 	-- \
 	-DLLVM_TARGETS_TO_BUILD=Native -DCMAKE_BUILD_TYPE=Release \
 	-DBOOTSTRAP_CMAKE_BUILD_TYPE=Release \
-	-DCLANG_ENABLE_BOOTSTRAP=ON -DCLANG_BOOTSTRAP_TARGETS="install-clang;install-clang-headers"
+	-DCLANG_ENABLE_BOOTSTRAP=ON -DCLANG_BOOTSTRAP_TARGETS="install-clang;install-clang-resource-headers"
 	
 This will produce a new image ``clang-debian8:staging`` from the latest
 upstream revision.
@@ -165,7 +165,7 @@
     ./llvm/utils/docker/build_docker_image.sh \
 	-s debian8 --d clang-debian8 -t "staging" \
 	--branch branches/google/stable \
-	-p clang -i install-clang -i install-clang-headers \
+	-p clang -i install-clang -i install-clang-resource-headers \
 	-- \
 	-DCMAKE_BUILD_TYPE=Release