llvm-build: Add "--write-library-table" option for generating the C++ library
dependency table used by llvm-config.

llvm-svn: 143628
diff --git a/llvm/docs/CommandGuide/llvm-build.pod b/llvm/docs/CommandGuide/llvm-build.pod
index 6f70ffe..2ccc1a2 100644
--- a/llvm/docs/CommandGuide/llvm-build.pod
+++ b/llvm/docs/CommandGuide/llvm-build.pod
@@ -36,6 +36,13 @@
 
 Print the component tree for the project.
 
+=item B<--write-library-table>
+
+Write out the C++ fragment which defines the components, library names, and
+required libraries. This C++ fragment is built into L<llvm-config|llvm-config>
+in order to provide clients with the list of required libraries for arbitrary
+component combinations.
+
 =item B<--write-llvmbuild>
 
 Write out new I<LLVMBuild.txt> files based on the loaded components. This is