Remove unused diagnostic. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@309888 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/DiagnosticParseKinds.td

@@ -893,8 +893,6 @@ def err_pragma_expected_clang_section_name : Error<
   "expected one of [bss|data|rodata|text] section kind in '#pragma %0'">;
 def err_pragma_clang_section_expected_equal : Error<
   "expected '=' following '#pragma clang section %select{invalid|bss|data|rodata|text}0'">;
-def err_pragma_clang_section_expected_name_or_clear : Error<
-  "expected section name or '\"\"' following '#pragma clang section %select{invalid|bss|data|rodata|text}0'">;
 def warn_pragma_expected_section_name : Warning<
   "expected a string literal for the section name in '#pragma %0' - ignored">,
   InGroup<IgnoredPragmas>;