Merge branch 'ab/pcre-jit-fixes'

A few simplification and bugfixes to PCRE interface. * ab/pcre-jit-fixes: grep: under --debug, show whether PCRE JIT is enabled grep: do not enter PCRE2_UTF mode on fixed matching grep: stess test PCRE v2 on invalid UTF-8 data grep: create a "is_fixed" member in "grep_pat" grep: consistently use "p->fixed" in compile_regexp() grep: stop using a custom JIT stack with PCRE v1 grep: stop "using" a custom JIT stack with PCRE v2 grep: remove overly paranoid BUG(...) code grep: use PCRE v2 for optimized fixed-string search grep: remove the kwset optimization grep: drop support for \0 in --fixed-strings <pattern> grep: make the behavior for NUL-byte in patterns sane grep tests: move binary pattern tests into their own file grep tests: move "grep binary" alongside the rest grep: inline the return value of a function call used only once t4210: skip more command-line encoding tests on MinGW grep: don't use PCRE2?_UTF8 with "log --encoding=<non-utf8>" log tests: test regex backends in "--encode=<enc>" tests