diff -ur root-6.18.04.orig/interpreter/llvm/src/tools/clang/lib/Lex/Lexer.cpp root-6.18.04/interpreter/llvm/src/tools/clang/lib/Lex/Lexer.cpp
--- root-6.18.04.orig/interpreter/llvm/src/tools/clang/lib/Lex/Lexer.cpp	2019-09-11 15:36:49.000000000 +0200
+++ root-6.18.04/interpreter/llvm/src/tools/clang/lib/Lex/Lexer.cpp	2020-02-06 14:36:14.580497452 +0100
@@ -2373,7 +2373,7 @@
         '/', '/', '/', '/',  '/', '/', '/', '/'
       };
       while (CurPtr+16 <= BufferEnd &&
-             !vec_any_eq(*(const vector unsigned char*)CurPtr, Slashes))
+             !vec_any_eq(*(const __vector unsigned char*)CurPtr, Slashes))
         CurPtr += 16;
 #else
       // Scan for '/' quickly.  Many block comments are very large.