Swift: remove an assert from swift headers

An interesting byproduct was finding a problematic `assert` in the
Swift headers. An incomplete `FallthroughStmt` was asserting on having
a destination. I did not find any other sensible way of getting rid of
the crash when running in debug mode than to patch the header.

misc/bazel/workspace.bzl

@@ -22,6 +22,10 @@ def codeql_workspace(repository_name = "codeql"):
                 _swift_prebuilt_version,
                 repo_arch,
             ),
+            patches = [
+                "@%s//swift/third_party/swift-llvm-support:patches/remove_getFallthrougDest_assert.patch" % repository_name,
+            ],
+            patch_args = ["-p1"],
             build_file = "@%s//swift/third_party/swift-llvm-support:BUILD.swift-prebuilt.bazel" % repository_name,
             sha256 = sha256,
         )

swift/third_party/swift-llvm-support/patches/remove_getFallthrougDest_assert.patch

@@ -0,0 +1,11 @@
+diff -ru a/include/swift/AST/Stmt.h b/include/swift/AST/Stmt.h
+--- a/include/swift/AST/Stmt.h	2022-09-21 12:56:54.000000000 +0200
++++ b/include/swift/AST/Stmt.h	2022-11-04 14:39:18.407971007 +0100
+@@ -920,7 +920,6 @@
+   /// Get the CaseStmt block to which the fallthrough transfers control.
+   /// Set during Sema.
+   CaseStmt *getFallthroughDest() const {
+-    assert(FallthroughDest && "fallthrough dest is not set until Sema");
+     return FallthroughDest;
+   }
+   void setFallthroughDest(CaseStmt *C) {