linux sparc compile issue

Hi,

while doing regular builds via buildroot autobuilders
a compile problem for sparc 32bit v8 was found.
It seems the defines for Linux are other than for Solaris.

Following patch fixes it for buildroot:

The gcc predefines for Linux are __sparc_v8__/__sparc_v7__

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>

diff -Nur postgresql-9.4.4.orig/src/include/storage/s_lock.h postgresql-9.4.4/src/include/storage/s_lock.h
--- postgresql-9.4.4.orig/src/include/storage/s_lock.h    2015-06-09 21:29:38.000000000 +0200
+++ postgresql-9.4.4/src/include/storage/s_lock.h    2015-08-09 19:57:06.000000000 +0200
@@ -420,12 +420,12 @@:        "=r"(_res), "+m"(*lock):        "r"(lock):        "memory");
-#if defined(__sparcv7)
+#if defined(__sparcv7) || defined(__sparc_v7__)    /*     * No stbar or membar available, luckily no actually produced
hardware    * requires a barrier.     */
 
-#elif defined(__sparcv8)
+#elif defined(__sparcv8) || defined(__sparc_v8__)    /* stbar is available (and required for both PSO, RMO), membar
isn't*/    __asm__ __volatile__ ("stbar     \n":::"memory");#else
 
@@ -438,13 +438,13 @@    return (int) _res;}
-#if defined(__sparcv7)
+#if defined(__sparcv7) || defined(__sparc_v7__)/* * No stbar or membar available, luckily no actually produced
hardware* requires a barrier. */#define S_UNLOCK(lock)        (*((volatile slock_t *) (lock)) = 0)
 
-#elif defined(__sparcv8)
+#elif defined(__sparcv8) || defined(__sparc_v8__)/* stbar is available (and required for both PSO, RMO), membar isn't
*/#defineS_UNLOCK(lock)    \do \