IRGen: repair a small regression on Windows (#78689)

Correct the IRGen for the standard library. The thinko here assumed that the else case would be evaluated for the standard library build. We ended up incorrectly handling the well-known VWTs from the runtime when building the standard library.

Author: compnerd

lib/IRGen/IRGenModule.cpp

@@ -1297,8 +1297,8 @@ IRGenModule::createStringConstant(StringRef Str, bool willBeRelativelyAddressed,
     if (NAME)                                                                  \
       return NAME;                                                             \
     NAME = Module.getOrInsertGlobal(SYM, FullExistentialTypeMetadataStructTy); \
-    if (!getSwiftModule()->isStdlibModule() ||                                 \
-        !getSwiftModule()->isStaticLibrary())                                  \
+    if (!getSwiftModule()->isStdlibModule() &&                                 \
+        !Context.getStdlibModule(true)->isStaticLibrary())                     \
       ApplyIRLinkage(IRLinkage::ExternalImport)                                \
           .to(cast<llvm::GlobalVariable>(NAME));                               \
     return NAME;                                                               \

test/IRGen/isolated_any_metadata.sil

@@ -1,5 +1,5 @@
-// RUN: %swift -emit-ir %s -target x86_64-apple-macosx10.10 -disable-legacy-type-info -parse-stdlib | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-ACCESSOR
-// RUN: %swift -emit-ir %s -target x86_64-unknown-linux-gnu -disable-legacy-type-info -parse-stdlib | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-DEMANGLE
+// RUN: %swift -emit-ir %s -target x86_64-apple-macosx10.10 -disable-legacy-type-info -parse-stdlib -module-name Swift | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-ACCESSOR
+// RUN: %swift -emit-ir %s -target x86_64-unknown-linux-gnu -disable-legacy-type-info -parse-stdlib -module-name Swift | %FileCheck -DINT=i64 %s -check-prefixes=CHECK,CHECK-DEMANGLE
 
 // REQUIRES: concurrency