[cmake] Remove LLVM_{BUILD,LINK}_LLVM_DYLIB options on Windows

Summary: The options aren't supported so they can be removed.

Reviewers: beanz, smeenai, compnerd

Reviewed By: compnerd

Subscribers: mgorny, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69877
diff --git a/llvm/docs/GettingStarted.rst b/llvm/docs/GettingStarted.rst
index 963de6f..72e161d 100644
--- a/llvm/docs/GettingStarted.rst
+++ b/llvm/docs/GettingStarted.rst
@@ -622,7 +622,8 @@
 |                         | default set of LLVM components that can be         |
 |                         | overridden with ``LLVM_DYLIB_COMPONENTS``. The     |
 |                         | default contains most of LLVM and is defined in    |
-|                         | ``tools/llvm-shlib/CMakelists.txt``.               |
+|                         | ``tools/llvm-shlib/CMakelists.txt``. This option is|
+|                         | not avialable on Windows.                          |
 +-------------------------+----------------------------------------------------+
 | LLVM_OPTIMIZED_TABLEGEN | Builds a release tablegen that gets used during    |
 |                         | the LLVM build. This can dramatically speed up     |