Remove traces of support for Sun Studio compiler

Per discussion, this compiler suite is no longer maintained, and
it has not been able to compile PostgreSQL since at least PostgreSQL
17.

This removes all the remaining support code for this compiler.

Note that the Solaris operating system continues to be supported, but
using GCC as the compiler.

Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/a0f817ee-fb86-483a-8a14-b6f7f5991b6e%40eisentraut.org

doc/src/sgml/dfunc.sgml

@@ -157,19 +157,12 @@ ld -Bshareable -o foo.so foo.o
     <listitem>
      <para>
       The compiler flag to create <acronym>PIC</acronym> is
-      <option>-KPIC</option> with the Sun compiler and
       <option>-fPIC</option> with <application>GCC</application>.  To
       link shared libraries, the compiler option is
-      <option>-G</option> with either compiler or alternatively
       <option>-shared</option> with <application>GCC</application>.
 <programlisting>
-cc -KPIC -c foo.c
-cc -G -o foo.so foo.o
-</programlisting>
-      or
-<programlisting>
 gcc -fPIC -c foo.c
-gcc -G -o foo.so foo.o
+gcc -shared -o foo.so foo.o
 </programlisting>
      </para>
     </listitem>

doc/src/sgml/installation.sgml

@@ -1676,10 +1676,6 @@ build-postgresql:
          using the GCC compiler:
 <screen>
 ./configure CC='gcc -m64' --enable-dtrace DTRACEFLAGS='-64' ...
-</screen>
-         Using Sun's compiler:
-<screen>
-./configure CC='/opt/SUNWspro/bin/cc -xtarget=native64' --enable-dtrace DTRACEFLAGS='-64' ...
 </screen>
         </para>
        </listitem>
@@ -3713,24 +3709,13 @@ xcrun --show-sdk-path
     <title>Required Tools</title>
 
     <para>
-     You can build with either GCC or Sun's compiler suite.  For
-     better code optimization, Sun's compiler is strongly recommended
-     on the SPARC architecture.  If
-     you are using Sun's compiler, be careful not to select
-     <filename>/usr/ucb/cc</filename>;
-     use <filename>/opt/SUNWspro/bin/cc</filename>.
+     Only GCC is supported as the compiler.  Sun's compiler suite is no longer
+     supported.
     </para>
 
     <para>
-     You can download Sun Studio
-     from <ulink url="https://www.oracle.com/technetwork/server-storage/solarisstudio/downloads/"></ulink>.
-     Many GNU tools are integrated into Solaris 10, or they are
-     present on the Solaris companion CD.  If you need packages for
-     older versions of Solaris, you can find these tools
-     at <ulink url="http://www.sunfreeware.com"></ulink>.
-     If you prefer
-     sources, look
-     at <ulink url="https://www.gnu.org/prep/ftp"></ulink>.
+     Many additional dependencies can be installed via the package management
+     system.
     </para>
    </sect3>
 
@@ -3753,27 +3738,6 @@ configure ... LDFLAGS="-R /usr/sfw/lib:/opt/sfw/lib:/usr/local/lib"
     </para>
    </sect3>
 
-   <sect3 id="installation-notes-solaris-comp-opt-perf">
-    <title>Compiling for Optimal Performance</title>
-
-    <para>
-     On the SPARC architecture, Sun Studio is strongly recommended for
-     compilation.  Try using the <option>-xO5</option> optimization
-     flag to generate significantly faster binaries.  Do not use any
-     flags that modify behavior of floating-point operations
-     and <varname>errno</varname> processing (e.g.,
-     <option>-fast</option>).
-    </para>
-
-    <para>
-     If you do not have a reason to use 64-bit binaries on SPARC,
-     prefer the 32-bit version.  The 64-bit operations are slower and
-     64-bit binaries are slower than the 32-bit variants.  On the
-     other hand, 32-bit code on the AMD64 CPU family is not native,
-     so 32-bit code is significantly slower on that CPU family.
-    </para>
-   </sect3>
-
    <sect3 id="installation-notes-solaris-using-dtrace">
     <title>Using DTrace for Tracing PostgreSQL</title>
 
@@ -3781,22 +3745,6 @@ configure ... LDFLAGS="-R /usr/sfw/lib:/opt/sfw/lib:/usr/local/lib"
      Yes, using DTrace is possible.  See <xref linkend="dynamic-trace"/> for
      further information.
     </para>
-
-    <para>
-     If you see the linking of the <command>postgres</command> executable abort with an
-     error message like:
-<screen>
-Undefined                       first referenced
- symbol                             in file
-AbortTransaction                    utils/probes.o
-CommitTransaction                   utils/probes.o
-ld: fatal: Symbol referencing errors. No output written to postgres
-collect2: ld returned 1 exit status
-make: *** [postgres] Error 1
-</screen>
-     your DTrace installation is too old to handle probes in static
-     functions.  You need Solaris 10u4 or newer to use DTrace.
-    </para>
    </sect3>
   </sect2>