mpich: enable -default on powerpc

Author: barracuda156

science/mpich/Portfile

@@ -85,9 +85,11 @@ dict set clist clang18 {macports-clang-18}
 dict set clist clang19 {macports-clang-19}
 
 # Only enable default (gcc), and Xcode clang, for MacOS 10.7 and later
-if { ${os.major} >= 11 } {
+if { ${os.major} >= 10 } {
     dict set clist default {}
-    dict set clist clang   {clang}
+    if { ${build_arch} ni [list ppc ppc64] } {
+        dict set clist clang {clang}
+    }
 } else {
     lappend clist_unsupported \
         default clang
@@ -152,7 +154,7 @@ if {${subport_enabled}} {
     mpiutil_set_binary_eligibility \
         ${subport} ${cname}
 
-    depends_build-append        port:pkgconfig
+    depends_build-append        path:bin/pkg-config:pkgconfig
     depends_lib-append          port:libxml2
 
     if {${cname} eq "mp"} {
@@ -184,6 +186,9 @@ if {${subport_enabled}} {
     # Hopefully avoid double-rpath issues.
     compilers.add_gcc_rpath_support no
 
+    compiler.blacklist-append \
+                    *gcc-4.0 *gcc-4.2
+
     if {${os.major} < 12} {
         # MPICH requires OpenCL version 1.2, which was not introduced until OS X Mountain Lion
         configure.args-append \