IRGen: Rename the section pointing to rodata of generic classes to __objc_clsrolist

Also emit it per default.

rdar://129299739

Author: aschwaighofer

include/swift/AST/IRGenOptions.h

@@ -554,7 +554,7 @@ class IRGenOptions {
         EnableGlobalISel(false), VirtualFunctionElimination(false),
         WitnessMethodElimination(false), ConditionalRuntimeRecords(false),
         InternalizeAtLink(false), InternalizeSymbols(false),
-        EmitGenericRODatas(false), NoPreallocatedInstantiationCaches(false),
+        EmitGenericRODatas(true), NoPreallocatedInstantiationCaches(false),
         DisableReadonlyStaticObjects(false), CollocatedMetadataFunctions(false),
         ColocateTypeDescriptors(true), UseRelativeProtocolWitnessTables(false),
         UseFragileResilientProtocolWitnesses(false),

lib/IRGen/GenDecl.cpp

@@ -1172,9 +1172,9 @@ void IRGenModule::emitGlobalLists() {
     if (IRGen.Opts.EmitGenericRODatas) {
       emitGlobalList(
           *this, GenericRODatas, "generic_ro_datas",
-          GetObjCSectionName("__swift_rodatas", "regular"),
+          GetObjCSectionName("__objc_clsrolist", "regular"),
           llvm::GlobalValue::InternalLinkage, Int8PtrTy, /*isConstant*/ false,
-          /*asContiguousArray*/ true, /*canBeStrippedByLinker*/ true);
+          /*asContiguousArray*/ true, /*canBeStrippedByLinker*/ false);
     }
 
     // Objective-C class references go in a variable with a meaningless

test/IRGen/generic_class_rodata_list.swift

@@ -30,7 +30,7 @@
 // CHECK:         .quad   0
 // CHECK:         .quad   __CLASS_METHODS__TtC25generic_class_rodata_list9Somethin
 
-// CHECK:        .section        __DATA,__swift_rodatas
+// CHECK:        .section        __DATA,__objc_clsrolist
 // CHECK:        .p2align        3
 // CHECK:_generic_ro_datas:
 // CHECK:        .quad   ___unnamed_1+40