Build C modules with -static-libgcc on Solaris

Without this patch we have the following error:

ImportError: ld.so.1: python3.7: fatal: libgcc_s.so.1: open failed: No such file or directory
(cherry picked from commit 00f4c2a)
(cherry picked from commit 2028ad6)

Author: enzbang

configure

@@ -9468,8 +9468,8 @@ then
 		;;
 	SunOS/5*)
 		if test "$GCC" = "yes" ; then
-			LDSHARED='$(CC) -shared'
-			LDCXXSHARED='$(CXX) -shared'
+			LDSHARED='$(CC) -static-libgcc -shared'
+			LDCXXSHARED='$(CXX) -static-libgcc -shared'
 		else
 			LDSHARED='$(CC) -G'
 			LDCXXSHARED='$(CXX) -G'

configure.ac

@@ -2587,8 +2587,8 @@ then
 		;;
 	SunOS/5*)
 		if test "$GCC" = "yes" ; then
-			LDSHARED='$(CC) -shared'
-			LDCXXSHARED='$(CXX) -shared'
+			LDSHARED='$(CC) -static-libgcc -shared'
+			LDCXXSHARED='$(CXX) -static-libgcc -shared'
 		else
 			LDSHARED='$(CC) -G'
 			LDCXXSHARED='$(CXX) -G'