build: remove SWIFT_BUILD_STDLIB check (NFC)

The swiftReflection library is only being built under a standard library
build.  The check is already present at a higher level, so there is no
need to replicate the check.

Author: compnerd

stdlib/public/Reflection/CMakeLists.txt

@@ -19,12 +19,9 @@ if (LLVM_ENABLE_ASSERTIONS)
     "${SWIFT_SOURCE_DIR}/lib/Demangling/NodeDumper.cpp")
 endif(LLVM_ENABLE_ASSERTIONS)
 
-if(SWIFT_BUILD_STDLIB)
-  add_swift_target_library(swiftReflection STATIC
-    ${swiftReflection_SOURCES}
-    C_COMPILE_FLAGS ${SWIFT_RUNTIME_CXX_FLAGS} -DswiftCore_EXPORTS
-    LINK_FLAGS ${SWIFT_RUNTIME_LINK_FLAGS}
-    SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
-    INSTALL_IN_COMPONENT dev)
-endif()
-
+add_swift_target_library(swiftReflection STATIC
+  ${swiftReflection_SOURCES}
+  C_COMPILE_FLAGS ${SWIFT_RUNTIME_CXX_FLAGS} -DswiftCore_EXPORTS
+  LINK_FLAGS ${SWIFT_RUNTIME_LINK_FLAGS}
+  SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
+  INSTALL_IN_COMPONENT dev)