Fix typos throughout the license files that somehow I and my reviewers

all missed!

Thanks to Alex Bradbury for pointing this out, and the fact that I never
added the intended `legacy` anchor to the developer policy. Add that
anchor too. With hope, this will cause the links to all resolve
successfully.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351731 91177308-0d34-0410-b5e6-96231b3b80d8

LICENSE.TXT

@@ -234,7 +234,7 @@ mechanisms:
    file.
 
 ==============================================================================
-Legacy LLVM License (ttps://llvm.org/docs/DeveloperPolicy.html#legacy):
+Legacy LLVM License (https://llvm.org/docs/DeveloperPolicy.html#legacy):
 ==============================================================================
 University of Illinois/NCSA
 Open Source License

docs/DeveloperPolicy.rst

@@ -851,6 +851,7 @@ holds though)::
    terms of that Grant to the ASF and to recipients of any software distributed
    by the ASF for any Apache software product whatsoever.
 
+.. _legacy:
 
 Legacy License Structure
 ------------------------

tools/msbuild/license.txt

@@ -234,7 +234,7 @@ mechanisms:
    file.
 
 ==============================================================================
-Legacy LLVM License (ttps://llvm.org/docs/DeveloperPolicy.html#legacy):
+Legacy LLVM License (https://llvm.org/docs/DeveloperPolicy.html#legacy):
 ==============================================================================
 University of Illinois/NCSA
 Open Source License