better gcc and clang support for afl-cc

docs/Changelog.md

@@ -20,7 +20,8 @@ sending a mail to <afl-users+subscribe@googlegroups.com>.
     - fixed endless loop for allow/blocklist lines starting with a
       comment (thanks to Zherya for reporting)
     - added AFL_LLVM_INSTRUMENT option NATIVE for native clang pc-guard
-      support (less performant than our own)
+      support (less performant than our own), GCC for old afl-gcc and
+      CLANG for old afl-clang
   - added dummy Makefile to instrumentation/
 
 

docs/env_variables.md

@@ -120,6 +120,8 @@ Then there are a few specific features that are only available in instrumentatio
         LTO - LTO instrumentation (see below)
         CTX - context sensitive instrumentation (see below)
         NGRAM-x - deeper previous location coverage (from NGRAM-2 up to NGRAM-16)
+        GCC - outdated gcc instrumentation
+        CLANG - outdated clang instrumentation
       In CLASSIC (default) and CFG/INSTRIM you can also specify CTX and/or
       NGRAM, seperate the options with a comma "," then, e.g.:
         `AFL_LLVM_INSTRUMENT=CFG,CTX,NGRAM-4`