sysutils/minipro: fix build with GCC-based architectures

This port needs new GCC to build on GCC architectures.

Actually respect CC by putting ?= instead of =.

Also respect CFLAGS and remove post-patch step, instead use a separate patch file.

PR: 238515
Approved by:	mat (mentor)
Differential Revision:	https://reviews.freebsd.org/D20819

sysutils/minipro/Makefile

@@ -12,7 +12,7 @@ LICENSE=	GPLv3
 
 RUN_DEPENDS=	bash:shells/bash
 
-USES=		gmake pkgconfig shebangfix
+USES=		compiler:c11 gmake pkgconfig shebangfix
 USE_GITLAB=	yes
 
 GL_ACCOUNT=	DavidGriffith
@@ -23,11 +23,6 @@ PLIST_FILES=	bin/minipro \
 		bin/miniprohex \
 		man/man1/minipro.1.gz
 
-post-patch:
-	@${REINPLACE_CMD} -e ' s|gcc|clang|g'  \
-			-e 's|share/||g' \
-		${WRKSRC}/Makefile
-
 post-install:
 	@${GZIP_CMD} ${STAGEDIR}${PREFIX}/man/man1/minipro.1
 	@${STRIP_CMD} ${STAGEDIR}${PREFIX}/bin/${PORTNAME}

sysutils/minipro/files/patch-Makefile

@@ -0,0 +1,31 @@
+--- Makefile.orig	2019-02-27 06:19:06 UTC
++++ Makefile
+@@ -1,16 +1,16 @@
+ # Install Configuration
+ 
+ # Your C compiler
+-CC=gcc
++CC?=gcc
+ #CC=clang
+ 
+ # Compiler options
+-CFLAGS = -g -O0 -Wall
++CFLAGS ?= -g -O0 -Wall
+ 
+ # Normally minipro is installed to /usr/local.  If you want to put it
+ # somewhere else, define that location here.
+ PREFIX ?= /usr/local
+-MANDIR ?= $(PREFIX)/share/man
++MANDIR ?= $(PREFIX)/man
+ 
+ # Some older releases of MacOS need some extra library flags.
+ #EXTRA_LIBS += "-framework Foundation -framework IOKit"
+@@ -58,7 +58,7 @@ OBJCOPY=objcopy
+ 
+ DIST_DIR = $(MINIPRO)-$(VERSION)
+ BIN_INSTDIR=$(DESTDIR)$(PREFIX)/bin
+-MAN_INSTDIR=$(DESTDIR)$(PREFIX)/share/man/man1
++MAN_INSTDIR=$(DESTDIR)$(PREFIX)/man/man1
+ 
+ UDEV_DIR=$(shell $(PKG_CONFIG) --define-variable=prefix=$(PREFIX) --silence-errors --variable=udevdir udev)
+ UDEV_RULES_INSTDIR=$(DESTDIR)$(UDEV_DIR)/rules.d