Import the swift-compiler-crashes test suite.

Add all compiler crash tests to the validation-test/compiler_crashers
subdirectory. Add a RUN: line to each test case according to the current
behavior of the Swift compiler.

Swift SVN r23418

validation-test/compiler_crashers/1122-swift-constraints-constraintsystem-solve.swift

@@ -0,0 +1,30 @@
+// RUN: not --crash %swift %s -parse
+
+// Distributed under the terms of the MIT license
+// Test case submitted to project by https://github.com/practicalswift (practicalswift)
+// Test case found by fuzzing
+
+struct j<l : o> {
+func a<l>() -> [j<l>] {
+return []
+l j l.n = {
+}
+{
+l) {
+n  }
+}
+protocol f {
+}
+class l: f{  class func n {}
+func a<i>() {
+b b {
+}
+}
+class a<f : b, l : b m f.l == l> {
+}
+protocol b {
+}
+struct j<n : b> : b {
+protocol p{
+}
+protocol g : e { func e