Shrink the binary by not super inlining all string concatenations.

Source/wtf/wtf.gypi

 # For GN compatibility, this file can not have any conditions.
 {
     'variables': {
         'wtf_files': [
             'ASCIICType.h',
             'AddressSpaceRandomization.cpp',
             'AddressSpaceRandomization.h',
             'Alignment.h',
             'ArrayBuffer.cpp',
             'ArrayBuffer.h',
@@ skipping 155 matching lines @@
             'text/AtomicStringHash.h',
             'text/Base64.cpp',
             'text/Base64.h',
             'text/CString.cpp',
             'text/CString.h',
             'text/IntegerToStringConversion.h',
             'text/StringBuffer.h',
             'text/StringBuilder.cpp',
             'text/StringBuilder.h',
             'text/StringCF.cpp',
+            'text/StringConcatenate.cpp',
             'text/StringConcatenate.h',
             'text/StringHash.h',
             'text/StringImpl.cpp',
             'text/StringImpl.h',
             'text/StringImplCF.cpp',
             'text/StringImplMac.mm',
             'text/StringMac.mm',
             'text/StringOperators.h',
             'text/StringStatics.cpp',
             'text/StringUTF8Adaptor.h',
@@ skipping 51 matching lines @@
             'text/TextCodecUTF8Test.cpp',
             'text/WTFStringTest.cpp',
         ],
         'wtf_unittest_helper_files': [
             'testing/WTFTestHelpers.cpp',
             'testing/WTFTestHelpers.h',
             'testing/WTFUnitTestHelpersExport.h',
         ],
     },
 }