[SourceKit] Add test case for crash triggered in swift::constraints::ConstraintGraph::addConstraint(swift::constraints::Constraint*)

Stack trace:

```
found code completion token A at offset 111
swift-ide-test: /path/to/swift/lib/Sema/ConstraintGraph.cpp:50: std::pair<ConstraintGraphNode &, unsigned int> swift::constraints::ConstraintGraph::lookupNode(swift::TypeVariableType *): Assertion `impl.getGraphIndex() < TypeVariables.size() && "Out-of-bounds index"' failed.
9  swift-ide-test  0x00000000009a229f swift::constraints::ConstraintGraph::addConstraint(swift::constraints::Constraint*) + 111
10 swift-ide-test  0x00000000009ae272 swift::constraints::ConstraintSystem::addConstraint(swift::constraints::Constraint*, bool, bool) + 258
11 swift-ide-test  0x00000000008de261 swift::constraints::ConstraintSystem::matchTypes(swift::Type, swift::Type, swift::constraints::TypeMatchKind, unsigned int, swift::constraints::ConstraintLocatorBuilder) + 4641
12 swift-ide-test  0x00000000008dcbbd swift::constraints::ConstraintSystem::matchTupleTypes(swift::TupleType*, swift::TupleType*, swift::constraints::TypeMatchKind, unsigned int, swift::constraints::ConstraintLocatorBuilder) + 445
13 swift-ide-test  0x00000000008e1f0c swift::constraints::ConstraintSystem::simplifyRestrictedConstraint(swift::constraints::ConversionRestrictionKind, swift::Type, swift::Type, swift::constraints::TypeMatchKind, unsigned int, swift::constraints::ConstraintLocatorBuilder) + 620
14 swift-ide-test  0x00000000008df773 swift::constraints::ConstraintSystem::matchTypes(swift::Type, swift::Type, swift::constraints::TypeMatchKind, unsigned int, swift::constraints::ConstraintLocatorBuilder) + 10035
15 swift-ide-test  0x00000000008e11e0 swift::constraints::ConstraintSystem::matchFunctionTypes(swift::FunctionType*, swift::FunctionType*, swift::constraints::TypeMatchKind, unsigned int, swift::constraints::ConstraintLocatorBuilder) + 400
16 swift-ide-test  0x00000000008e062b swift::constraints::ConstraintSystem::matchTypes(swift::Type, swift::Type, swift::constraints::TypeMatchKind, unsigned int, swift::constraints::ConstraintLocatorBuilder) + 13803
17 swift-ide-test  0x00000000008dd909 swift::constraints::ConstraintSystem::matchTypes(swift::Type, swift::Type, swift::constraints::TypeMatchKind, unsigned int, swift::constraints::ConstraintLocatorBuilder) + 2249
18 swift-ide-test  0x00000000008e910f swift::constraints::ConstraintSystem::simplifyConstraint(swift::constraints::Constraint const&) + 639
19 swift-ide-test  0x00000000009ae187 swift::constraints::ConstraintSystem::addConstraint(swift::constraints::Constraint*, bool, bool) + 23
20 swift-ide-test  0x00000000009bdbb5 swift::TypeChecker::callWitness(swift::Expr*, swift::DeclContext*, swift::ProtocolDecl*, swift::ProtocolConformance*, swift::DeclName, llvm::MutableArrayRef<swift::Expr*>, swift::Diag<>) + 1797
24 swift-ide-test  0x0000000000ae636e swift::Expr::walk(swift::ASTWalker&) + 46
25 swift-ide-test  0x00000000009b9af6 swift::constraints::ConstraintSystem::applySolution(swift::constraints::Solution&, swift::Expr*, swift::Type, bool, bool, bool) + 502
26 swift-ide-test  0x000000000091ebdb swift::TypeChecker::typeCheckExpression(swift::Expr*&, swift::DeclContext*, swift::Type, swift::ContextualTypePurpose, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::ExprTypeCheckListener*) + 683
28 swift-ide-test  0x00000000009d52b9 swift::constraints::ConstraintSystem::diagnoseFailureForExpr(swift::Expr*) + 4009
29 swift-ide-test  0x00000000009d87ee swift::constraints::ConstraintSystem::salvage(llvm::SmallVectorImpl<swift::constraints::Solution>&, swift::Expr*) + 4046
30 swift-ide-test  0x0000000000918755 swift::TypeChecker::solveForExpression(swift::Expr*&, swift::DeclContext*, swift::Type, swift::FreeTypeVariableBinding, swift::ExprTypeCheckListener*, swift::constraints::ConstraintSystem&, llvm::SmallVectorImpl<swift::constraints::Solution>&, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 661
31 swift-ide-test  0x000000000091eb69 swift::TypeChecker::typeCheckExpression(swift::Expr*&, swift::DeclContext*, swift::Type, swift::ContextualTypePurpose, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>, swift::ExprTypeCheckListener*) + 569
33 swift-ide-test  0x0000000000981de6 swift::TypeChecker::typeCheckTopLevelCodeDecl(swift::TopLevelCodeDecl*) + 134
34 swift-ide-test  0x0000000000905e6d swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int) + 1405
35 swift-ide-test  0x0000000000774192 swift::CompilerInstance::performSema() + 2946
36 swift-ide-test  0x000000000071cc33 main + 35011
Stack dump:
0.	Program arguments: swift-ide-test -code-completion -code-completion-token=A -source-filename=<INPUT-FILE>
1.	While type-checking expression at [<INPUT-FILE>:2:1 - line:2:7] RangeText="[[map)"
2.	While type-checking expression at [<INPUT-FILE>:2:1 - line:2:7] RangeText="[[map)"
```

Author: practicalswift

validation-test/IDE/crashers/013-swift-constraints-constraintgraph-addconstraint.swift

@@ -0,0 +1,2 @@
+// RUN: not --crash %target-swift-ide-test -code-completion -code-completion-token=A -source-filename=%s
+[[map)#^A^#