pcre.cmake: always check the library with check_library_exists()

even if pkg-config has it. otherwise build dependencies
aren't detected.

cmake/pcre.cmake

@@ -81,18 +81,15 @@ MACRO (CHECK_PCRE)
  FIND_PACKAGE(PkgConfig QUIET)
  PKG_CHECK_MODULES(PCRE libpcre2-8)
  # in case pkg-config or libpcre2-8.pc is not installed:
- IF(NOT PCRE_FOUND)
- UNSET(PCRE_FOUND CACHE)
- CHECK_LIBRARY_EXISTS(pcre2-8 pcre2_match_8 "" PCRE_FOUND)
- ENDIF()
+ CHECK_LIBRARY_EXISTS(pcre2-8 pcre2_match_8 "${PCRE_LIBRARY_DIRS}" HAVE_PCRE2_MATCH_8)
  ENDIF()
- IF(NOT PCRE_FOUND OR WITH_PCRE STREQUAL "bundled")
+ IF(NOT HAVE_PCRE2_MATCH_8 OR WITH_PCRE STREQUAL "bundled")
  IF (WITH_PCRE STREQUAL "system")
  MESSAGE(FATAL_ERROR "system pcre2-8 library is not found or unusable")
  ENDIF()
  BUNDLE_PCRE2()
  ELSE()
- CHECK_LIBRARY_EXISTS(pcre2-posix PCRE2regcomp "" NEEDS_PCRE2_DEBIAN_HACK)
+ CHECK_LIBRARY_EXISTS(pcre2-posix PCRE2regcomp "${PCRE_LIBRARY_DIRS}" NEEDS_PCRE2_DEBIAN_HACK)
  IF(NEEDS_PCRE2_DEBIAN_HACK)
  SET(PCRE2_DEBIAN_HACK "-Dregcomp=PCRE2regcomp -Dregexec=PCRE2regexec -Dregerror=PCRE2regerror -Dregfree=PCRE2regfree")
  ENDIF()