If we are extracting a basic block that ends in an invoke call, we must also extract the landing pad block. Otherwise, there will be a situation where the invoke's unwind edge lands on a non-landing pad.
If we are extracting a basic block that ends in an invoke call, we must also
extract the landing pad block. Otherwise, there will be a situation where the
invoke's unwind edge lands on a non-landing pad.

We also forbid the user from extracting the landing pad block by itself. Again,
this is not a valid transformation.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@140083 91177308-0d34-0410-b5e6-96231b3b80d8

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