Serialization: allow IS_STATIC_LIBRARY to be deserialised properly

Properly encode the field metadata to permit the deserialization by
`llvm-bcanalyzer` for aiding debugging.

Author: compnerd

lib/Serialization/Serialization.cpp

@@ -837,6 +837,7 @@ void Serializer::writeBlockInfoBlock() {
   BLOCK_RECORD(options_block, SDK_PATH);
   BLOCK_RECORD(options_block, XCC);
   BLOCK_RECORD(options_block, IS_SIB);
+  BLOCK_RECORD(options_block, IS_STATIC_LIBRARY);
   BLOCK_RECORD(options_block, IS_TESTABLE);
   BLOCK_RECORD(options_block, ARE_PRIVATE_IMPORTS_ENABLED);
   BLOCK_RECORD(options_block, RESILIENCE_STRATEGY);

test/Serialization/static.swift

@@ -0,0 +1,12 @@
+// RUN: %empty-directory(%t)
+
+// RUN: %target-swift-frontend -emit-module -o %t %s
+// RUN: llvm-bcanalyzer -dump %t/static.swiftmodule | %FileCheck %s -check-prefix CHECK -check-prefix DYNAMIC
+
+// RUN: %target-swift-frontend -static -emit-module -o %t %s
+// RUN: llvm-bcanalyzer -dump %t/static.swiftmodule | %FileCheck %s -check-prefix CHECK -check-prefix STATIC
+
+// CHECK: <MODULE_BLOCK {{.*}}>
+// CHECK-STATIC: <IS_STATIC abbrevid={{[0-9]+}}/>
+// CHECK-DYNAMIC-NOT: <IS_STATIC abbrevid={{[0-9]+}}/>
+// CHECK: </MODULE_BLOCK>