Fail cleanly for certain invalid manglings

There are certainly more such issues in this code, but this is
one that was recently reported.

While here, re-enable some disabled test cases that currently pass.

Resolves rdar://104671103

Author: tbkka

lib/Demangling/Demangler.cpp

@@ -2141,7 +2141,8 @@ NodePointer Demangler::demangleImplFunctionType() {
       return nullptr;
 
     auto subsNode = createNode(Node::Kind::ImplInvocationSubstitutions);
-    assert(Substitutions.size() == 1);
+    if (Substitutions.size() != 1)
+      return nullptr;
     subsNode->addChild(Substitutions[0], *this);
     if (SubstitutionRetroConformances)
       subsNode->addChild(SubstitutionRetroConformances, *this);

test/Demangle/Inputs/manglings.txt

@@ -206,7 +206,6 @@ _TTSgSi__xyz ---> _TTSgSi__xyz
 _TTSr5Si___TF4test7genericurFxx ---> generic not re-abstracted specialization <Swift.Int> of test.generic<A>(A) -> A
 _TTSrq5Si___TF4test7genericurFxx ---> generic not re-abstracted specialization <serialized, Swift.Int> of test.generic<A>(A) -> A
 _TPA__TTRXFo_oSSoSS_dSb_XFo_iSSiSS_dSb_ ---> {T:_TTRXFo_oSSoSS_dSb_XFo_iSSiSS_dSb_} partial apply forwarder for reabstraction thunk helper from @callee_owned (@in Swift.String, @in Swift.String) -> (@unowned Swift.Bool) to @callee_owned (@owned Swift.String, @owned Swift.String) -> (@unowned Swift.Bool)
-to @callee_owned (@in Swift.String, @in Swift.String) -> (@unowned Swift.Bool)
 _TPAo__TTRGrXFo_dGSPx__dGSPx_zoPs5Error__XFo_iGSPx__iGSPx_zoPS___ ---> {T:_TTRGrXFo_dGSPx__dGSPx_zoPs5Error__XFo_iGSPx__iGSPx_zoPS___} partial apply ObjC forwarder for reabstraction thunk helper <A> from @callee_owned (@in Swift.UnsafePointer<A>) -> (@out Swift.UnsafePointer<A>, @error @owned Swift.Error) to @callee_owned (@unowned Swift.UnsafePointer<A>) -> (@unowned Swift.UnsafePointer<A>, @error @owned Swift.Error)
 _T0S2SSbIxxxd_S2SSbIxiid_TRTA ---> {T:_T0S2SSbIxxxd_S2SSbIxiid_TR} partial apply forwarder for reabstraction thunk helper from @callee_owned (@owned Swift.String, @owned Swift.String) -> (@unowned Swift.Bool) to @callee_owned (@in Swift.String, @in Swift.String) -> (@unowned Swift.Bool)
 _T0SPyxGAAs5Error_pIxydzo_A2AsAB_pIxirzo_lTRTa ---> {T:_T0SPyxGAAs5Error_pIxydzo_A2AsAB_pIxirzo_lTR} partial apply ObjC forwarder for reabstraction thunk helper <A> from @callee_owned (@unowned Swift.UnsafePointer<A>) -> (@unowned Swift.UnsafePointer<A>, @error @owned Swift.Error) to @callee_owned (@in Swift.UnsafePointer<A>) -> (@out Swift.UnsafePointer<A>, @error @owned Swift.Error)
@@ -377,10 +376,10 @@ $sxq_Ilgnr_D ---> @differentiable(_linear) @callee_guaranteed (@in_guaranteed A)
 $sS3fIedgyywd_D ---> @escaping @differentiable @callee_guaranteed (@unowned Swift.Float, @unowned @noDerivative Swift.Float) -> (@unowned Swift.Float)
 $sS5fIertyyywddw_D ---> @escaping @differentiable(reverse) @convention(thin) (@unowned Swift.Float, @unowned Swift.Float, @unowned @noDerivative Swift.Float) -> (@unowned Swift.Float, @unowned @noDerivative Swift.Float)
 $syQo ---> $syQo
-$s0059xxxxxxxxxxxxxxx_ttttttttBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBee -> $s0059xxxxxxxxxxxxxxx_ttttttttBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBee
+$s0059xxxxxxxxxxxxxxx_ttttttttBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBee ---> $s0059xxxxxxxxxxxxxxx_ttttttttBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBee
 $sx1td_t ---> (t: A...)
-$s7example1fyyYaF -> example.f() async -> ()
-$s7example1fyyYaKF -> example.f() async throws -> ()
+$s7example1fyyYaF ---> example.f() async -> ()
+$s7example1fyyYaKF ---> example.f() async throws -> ()
 s7example1fyyYjfYaKF -> example.f@differentiable(_forward) () async throws -> ()
 s7example1fyyYjrYaKF -> example.f@differentiable(reverse) () async throws -> ()
 s7example1fyyYjdYaKF -> example.f@differentiable () async throws -> ()
@@ -432,8 +431,8 @@ $s21back_deploy_attribute0A12DeployedFuncyyFTwB ---> back deployment fallback fo
 $s4test3fooyyAA1P_px1TRts_XPlF ---> test.foo<A>(any test.P<Self.T == A>) -> ()
 $s4test3fooyyAA1P_pSS1TAaCPRts_Si1UAERtsXPF ---> test.foo(any test.P<Self.test.P.T == Swift.String, Self.test.P.U == Swift.Int>) -> ()
 $s4test3FooVAAyyAA1P_pF ---> test.Foo.test(test.P) -> ()
-$sxxxIxzCXxxxesy -> $sxxxIxzCXxxxesy
-$Sxxx_x_xxIxzCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC$x -> $Sxxx_x_xxIxzCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC$x
+$sxxxIxzCXxxxesy ---> $sxxxIxzCXxxxesy
+$Sxxx_x_xxIxzCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC$x ---> $Sxxx_x_xxIxzCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC$x
 $sxIeghHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTATQ0_ ---> {T:$sxIeghHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTR} (1) await resume partial function for partial apply forwarder for reabstraction thunk helper <A, B where A: Swift.Sendable, B == Swift.Never> from @escaping @callee_guaranteed @Sendable @async () -> (@out A) to @escaping @callee_guaranteed @async () -> (@out A, @error @owned Swift.Error)
 $sxIeghHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTQ0_ ---> {T:} (1) await resume partial function for reabstraction thunk helper <A, B where A: Swift.Sendable, B == Swift.Never> from @escaping @callee_guaranteed @Sendable @async () -> (@out A) to @escaping @callee_guaranteed @async () -> (@out A, @error @owned Swift.Error)
 $sxIeghHr_xs5Error_pIegHrzo_s8SendableRzs5NeverORs_r0_lTRTY0_ ---> {T:} (1) suspend resume partial function for reabstraction thunk helper <A, B where A: Swift.Sendable, B == Swift.Never> from @escaping @callee_guaranteed @Sendable @async () -> (@out A) to @escaping @callee_guaranteed @async () -> (@out A, @error @owned Swift.Error)
@@ -457,3 +456,4 @@ $s9MacroUser016testFreestandingA9ExpansionyyF4Foo3L_V23bitwidthNumberedStructsfM
 @__swiftmacro_18macro_expand_peers1SV1f20addCompletionHandlerfMp_ ---> peer macro @addCompletionHandler expansion #1 of f in macro_expand_peers.S
 @__swiftmacro_9MacroUser16MemberNotCoveredV33_4361AD9339943F52AE6186DD51E04E91Ll0dE0fMf0_ ---> freestanding macro expansion #2 of NotCovered(in _4361AD9339943F52AE6186DD51E04E91) in MacroUser.MemberNotCovered
 $sxSo8_NSRangeVRlzCRl_Cr0_llySo12ModelRequestCyxq_GIsPetWAlYl_TC ---> coroutine continuation prototype for @escaping @convention(thin) @convention(witness_method) @yield_once <A, B where A: AnyObject, B: AnyObject> @substituted <A> (@inout A) -> (@yields @inout __C._NSRange) for <__C.ModelRequest<A, B>>
+$SyyySGSS_IIxxxxx____xsIyFSySIxx_@xIxx____xxI ---> $SyyySGSS_IIxxxxx____xsIyFSySIxx_@xIxx____xxI