Merge pull request #9780 from milseman/the_missing_link

[stubs] Autolink against icucore on Darwin.

Author: milseman

lib/Driver/ToolChains.cpp

@@ -1237,7 +1237,6 @@ toolchains::Darwin::constructInvocation(const LinkJobAction &job,
     getRuntimeStaticLibraryPath(StaticRuntimeLibPath, context.Args, *this);
     Arguments.push_back(context.Args.MakeArgString(StaticRuntimeLibPath));
     Arguments.push_back("-lc++");
-    Arguments.push_back("-licucore");
     Arguments.push_back("-framework");
     Arguments.push_back("Foundation");
     Arguments.push_back("-force_load_swift_libs");

stdlib/public/stubs/UnicodeNormalization.cpp

@@ -317,6 +317,10 @@ int32_t ubrk_preceding(UBreakIterator *, int32_t);
 int32_t ubrk_following(UBreakIterator *, int32_t);
 void ubrk_setText(UBreakIterator *, const UChar *, int32_t, UErrorCode *);
 }
+
+// Force an autolink with ICU
+asm(".linker_option \"-licucore\"\n");
+
 #endif // defined(__APPLE__)
 
 void swift::__swift_stdlib_ubrk_close(