[SIL] Honor @inlinable in resilient modules for enum exhaustivity

Otherwise, we'll generate inlinable code over a supposedly non-frozen
enum that doesn't actually contain a 'default'.

Author: jrose-apple

lib/SIL/SILInstructions.cpp

@@ -1424,9 +1424,9 @@ namespace {
     EnumDecl *decl = enumType.getEnumOrBoundGenericEnum();
     assert(decl && "switch_enum operand is not an enum");
 
-    // FIXME: Get expansion from SILFunction
-    if (!decl->isEffectivelyExhaustive(inst->getModule().getSwiftModule(),
-                                       ResilienceExpansion::Maximal)) {
+    const SILFunction *F = inst->getFunction();
+    if (!decl->isEffectivelyExhaustive(F->getModule().getSwiftModule(),
+                                       F->getResilienceExpansion())) {
       return nullptr;
     }
 

lib/SIL/SILVerifier.cpp

@@ -3705,10 +3705,9 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
     }
 
     // If the select is non-exhaustive, we require a default.
-    // FIXME: Get the resilience expansion from the function.
     bool isExhaustive =
         eDecl->isEffectivelyExhaustive(F.getModule().getSwiftModule(),
-                                       ResilienceExpansion::Maximal);
+                                       F.getResilienceExpansion());
     require((isExhaustive && unswitchedElts.empty()) || I->hasDefault(),
             "nonexhaustive select_enum must have a default destination");
     if (I->hasDefault()) {
@@ -3877,10 +3876,9 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
     }
 
     // If the switch is non-exhaustive, we require a default.
-    // FIXME: Get the resilience expansion from the function.
     bool isExhaustive =
         uDecl->isEffectivelyExhaustive(F.getModule().getSwiftModule(),
-                                       ResilienceExpansion::Maximal);
+                                       F.getResilienceExpansion());
     require((isExhaustive && unswitchedElts.empty()) || SOI->hasDefault(),
             "nonexhaustive switch_enum must have a default destination");
     if (SOI->hasDefault()) {

lib/SILOptimizer/Transforms/SILCodeMotion.cpp

@@ -317,10 +317,10 @@ void BBEnumTagDataflowState::handlePredCondSelectEnum(CondBranchInst *CondBr) {
   // know the true branch must be the other tag.
   if (EnumDecl *E = Operand->getType().getEnumOrBoundGenericEnum()) {
     // We can't do this optimization on non-exhaustive enums.
-    // FIXME: Get resilience expansion from the function.
+    const SILFunction *Fn = CondBr->getFunction();
     bool IsExhaustive =
-        E->isEffectivelyExhaustive(CondBr->getModule().getSwiftModule(),
-                                   ResilienceExpansion::Maximal);
+        E->isEffectivelyExhaustive(Fn->getModule().getSwiftModule(),
+                                   Fn->getResilienceExpansion());
     if (!IsExhaustive)
       return;
     // Look for a single other element on this enum.

lib/SILOptimizer/Transforms/SimplifyCFG.cpp

@@ -1583,10 +1583,9 @@ bool SimplifyCFG::simplifyCondBrBlock(CondBranchInst *BI) {
     EnumElementDecl *FirstElt = *Iter;
 
     // We can't do this optimization on non-exhaustive enums.
-    // FIXME: Get the resilience expansion from the function.
     bool IsExhaustive =
         E->isEffectivelyExhaustive(Fn.getModule().getSwiftModule(),
-                                   ResilienceExpansion::Maximal);
+                                   Fn.getResilienceExpansion());
 
     if (IsExhaustive
         && SEI->getNumCases() >= 1