C#/Ruby/Swift: Tweaks to documentation

Co-authored-by: Anders Schack-Mulligen <aschackmull@users.noreply.github.com>

csharp/ql/lib/semmle/code/csharp/controlflow/BasicBlocks.qll

@@ -211,8 +211,8 @@ final class BasicBlock extends BasicBlocksImpl::BasicBlock {
    *
    * Edge dominance is similar to node dominance except it concerns edges
    * instead of nodes: A basic block is dominated by a _basic block_ `bb` if it
-   * can only be reached through `bb` and dominated by an _edge_ `s` if it can
-   * only be reached through `s`.
+   * can only be reached through `bb` and dominated by an _edge_ `e` if it can
+   * only be reached through `e`.
    *
    * Note that where all basic blocks (except the entry basic block) are
    * strictly dominated by at least one basic block, a basic block may not be

shared/controlflow/codeql/controlflow/BasicBlock.qll

@@ -264,17 +264,17 @@ module Make<LocationSig Location, InputSig<Location> Input> {
   predicate dominatingEdge(BasicBlock bb1, BasicBlock bb2) {
     bb1.getASuccessor(_) = bb2 and
     bbIDominates(bb1, bb2) and
-    // The above is not sufficient to ensure that `bb1` can only be reached
+    // The above is not sufficient to ensure that `bb2` can only be reached
     // through `(bb1, bb2)`. To see why, consider this example corresponding to
-    // an `if` statement without an `else` block and whe `A` is the basic block
+    // an `if` statement without an `else` block where `A` is the basic block
     // following the `if` statement:
     // ```
     // ... --> cond --[true]--> ... --> A
-    //           \                      /
+    //           \                      ^
     //            ----[false]-----------
     // ```
     // Here `A` is a direct successor of `cond` along the `false` edge and it
-    // is immediately dominated by `cond`, but `A` is not controlled by the
+    // is immediately dominated by `cond`, but `A` is not dominated by the
     // `false` edge since it is also possible to reach `A` via the `true`
     // edge.
     //