[IRGen] Use 32-bit string hash for type id.

Author: nate-chandler

lib/IRGen/GenPointerAuth.cpp

@@ -778,7 +778,9 @@ llvm::ConstantInt *IRGenModule::getMallocTypeId(llvm::Function *fn) {
     // materialized value.
     return llvm::ConstantInt::get(Int64Ty, 0);
   }
-  return getDiscriminatorForString(*this, fn->getName());
+  uint64_t hash = llvm::getStableSipHash(fn->getName());
+  uint32_t hash32 = (hash % std::numeric_limits<uint32_t>::max()) + 1;
+  return llvm::ConstantInt::get(Int64Ty, hash32);
 }
 
 llvm::ConstantInt* IRGenFunction::getMallocTypeId() {

test/IRGen/yield_once_enable_emit_type_malloc_coro_frame.sil

@@ -11,8 +11,8 @@ sil @marker : $(Builtin.Int32) -> ()
 // CHECK-SAME:  [[CORO_ATTRIBUTES:#[0-9]+]]
 sil @test_simple : $@yield_once () -> () {
 entry:
-  // CHECK-32: [[ID:%.*]] = call token (i32, i32, ptr, ptr, ptr, ptr, ...) @llvm.coro.id.retcon.once(i32 [[BUFFER_SIZE]], i32 [[BUFFER_ALIGN:4]], ptr %0, ptr @"$sIetA_TC", ptr @__swift_coroFrameAllocStub, ptr @free, i64 38223)
-  // CHECK-64: [[ID:%.*]] = call token (i32, i32, ptr, ptr, ptr, ptr, ...) @llvm.coro.id.retcon.once(i32 [[BUFFER_SIZE]], i32 [[BUFFER_ALIGN:8]], ptr %0, ptr @"$sIetA_TC", ptr @__swift_coroFrameAllocStub, ptr @free, i64 38223)
+  // CHECK-32: [[ID:%.*]] = call token (i32, i32, ptr, ptr, ptr, ptr, ...) @llvm.coro.id.retcon.once(i32 [[BUFFER_SIZE]], i32 [[BUFFER_ALIGN:4]], ptr %0, ptr @"$sIetA_TC", ptr @__swift_coroFrameAllocStub, ptr @free, i64 121146903)
+  // CHECK-64: [[ID:%.*]] = call token (i32, i32, ptr, ptr, ptr, ptr, ...) @llvm.coro.id.retcon.once(i32 [[BUFFER_SIZE]], i32 [[BUFFER_ALIGN:8]], ptr %0, ptr @"$sIetA_TC", ptr @__swift_coroFrameAllocStub, ptr @free, i64 121146903)
   // CHECK-NEXT:    [[BEGIN:%.*]] = call ptr @llvm.coro.begin(token [[ID]], ptr null)
 
   // CHECK-NEXT:    call swiftcc void @marker(i32 1000)