[swiftc (70 vs. 5162)] Add crasher in swift::Lowering::emitConditionalCheckedCast(...)
Add test case for crash triggered in `swift::Lowering::emitConditionalCheckedCast(...)`.
Current number of unresolved compiler crashers: 70 (5162 resolved)
Assertion failure in [`lib/SILGen/SILGenDynamicCast.cpp (line 131)`](https://github.com/apple/swift/blob/master/lib/SILGen/SILGenDynamicCast.cpp#L131):
```
Assertion `operand.getType().isAddress()' failed.
When executing: void (anonymous namespace)::CheckedCastEmitter::emitConditional(swift::Lowering::ManagedValue, swift::CastConsumptionKind, swift::Lowering::SGFContext, const std::function<void (ManagedValue)> &, const std::function<void ()> &)
```
Assertion context:
```
// Emit the branch.
SILValue scalarOperandValue;
SILValue resultBuffer;
if (Strategy == CastStrategy::Address) {
assert(operand.getType().isAddress());
resultBuffer =
createAbstractResultBuffer(hasAbstraction, origTargetTL, ctx);
SGF.B.createCheckedCastAddrBranch(Loc, consumption,
operand.forward(SGF), SourceType,
resultBuffer, TargetType,
```
Stack trace:
```
swift: /path/to/swift/lib/SILGen/SILGenDynamicCast.cpp:131: void (anonymous namespace)::CheckedCastEmitter::emitConditional(swift::Lowering::ManagedValue, swift::CastConsumptionKind, swift::Lowering::SGFContext, const std::function<void (ManagedValue)> &, const std::function<void ()> &): Assertion `operand.getType().isAddress()' failed.
9 swift 0x000000000099297c swift::Lowering::emitConditionalCheckedCast(swift::Lowering::SILGenFunction&, swift::SILLocation, swift::Lowering::ManagedValue, swift::Type, swift::Type, swift::CheckedCastKind, swift::Lowering::SGFContext) + 2012
21 swift 0x0000000000944aa2 swift::SILModule::constructSIL(swift::ModuleDecl*, swift::SILOptions&, swift::FileUnit*, llvm::Optional<unsigned int>, bool, bool) + 498
22 swift 0x0000000000945016 swift::performSILGeneration(swift::FileUnit&, swift::SILOptions&, llvm::Optional<unsigned int>, bool) + 118
24 swift 0x00000000007e0947 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2887
25 swift 0x00000000007a8e08 main + 2984
Stack dump:
0. Program arguments: /path/to/swift/bin/swift -frontend -c -primary-file validation-test/compiler_crashers/28420-swift-lowering-emitconditionalcheckedcast.swift -target x86_64-unknown-linux-gnu -disable-objc-interop -module-name main -o /tmp/28420-swift-lowering-emitconditionalcheckedcast-0c2422.o
1. While emitting SIL for 'b' at validation-test/compiler_crashers/28420-swift-lowering-emitconditionalcheckedcast.swift:14:1
<unknown>:0: error: unable to execute command: Aborted
<unknown>:0: error: compile command failed due to signal (use -v to see invocation)
```
swift
c2218e3e - [swiftc (70 vs. 5162)] Add crasher in swift::Lowering::emitConditionalCheckedCast(...)