Update ChangeLog file
Update ChangeLog file (related to 7.5.0)
Fix CFLAGS in configure regarding -O flag passing to SunCC compiler

* configure.ac (CFLAGS): Add -O flag if Solaris SunCC (i.e., not GCC)
regardless of threads support (i.e., even in case it is off).
Fix 'illegal option -xassembler-with-cpp' error (Oracle SunCC)

* Makefile.am (ASM_CPP_OPTIONS): Move comment to configure.ac.
* Makefile.am (COMPILER_XLC): Rename to ASM_WITH_CPP_UNSUPPORTED.
* configure.ac (COMPILER_XLC): Likewise.
* configure.ac (compiler_suncc): New variable (set to "yes" if Solaris
Sun C compiler).
* configure.ac (ASM_WITH_CPP_UNSUPPORTED): Define not only for
compiler_xlc but also for compiler_suncc.