Teach Solaris that _XOPEN_SOURCE=600 really menas XPG6

In git-compat-util.h, we do #define _XOPEN_SOURCE 600 #define _XOPEN_SOURCE_EXTENDED 1 unless we are on BSD or SCO. On OpenSolaris (200811), /usr/include/sys/feature_tests.h has this nice table: Feature Test Macro Specification ------------------------------------------------ ------------- _XOPEN_SOURCE XPG3 _XOPEN_SOURCE && _XOPEN_VERSION = 4 XPG4 _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED = 1 XPG4v2 _XOPEN_SOURCE = 500 XPG5 _XOPEN_SOURCE = 600 (or POSIX_C_SOURCE=200112L) XPG6 Later in the same header, compilation with -c99 is made to fail if _XPG6 is not set, like this: #if defined(_STDC_C99) && (defined(__XOPEN_OR_POSIX) && !defined(_XPG6)) #error "Compiler or options invalid for pre-UNIX 03 X/Open applications \ and pre-2001 POSIX applications" #elif ... The problem is that they check things in an order that is inconvenient for us. When they see _XOPEN_SOURCE_EXTENDED, they declare that we are XPG4v2, regardless of the value of _XOPEN_SOURCE. To work around this problem, do not define _XOPEN_SOURCE_EXTENDED on Sun's. Signed-off-by: Junio C Hamano <gitster@pobox.com>