File llvm-fix-find-gcc5-install.patch of Package llvm18

Index: clang-18.1.0rc1.src/lib/Driver/ToolChains/Gnu.cpp
===================================================================
--- clang-18.1.0rc1.src.orig/lib/Driver/ToolChains/Gnu.cpp
+++ clang-18.1.0rc1.src/lib/Driver/ToolChains/Gnu.cpp
@@ -2179,7 +2179,7 @@ Generic_GCC::GCCVersion Generic_GCC::GCC
     return GoodVersion;
   }
 
-  if (!TryParseNumber(MinorStr, GoodVersion.Minor))
+  if (!MinorStr.str().empty() && !TryParseNumber(MinorStr, GoodVersion.Minor))
     return BadVersion;
   GoodVersion.MinorStr = MinorStr;