sci-chemistry/xcrysden: replace patch with flag-o-matic to set -fcommon

Signed-off-by: Patrick J Taylor <patrick.joseph.taylor@gmail.com>

sci-chemistry/xcrysden/files/xcrysden-1.6.2-gcc_flags.patch

@@ -1,14 +0,0 @@
-Adds -fcommon to CFLAGS to allow compilation on more recent GCC.
-diff --git a/system/Make.sys-shared b/system/Make.sys-shared
-index 51891e7..f89f876 100644
---- a/system/Make.sys-shared
-+++ b/system/Make.sys-shared
-@@ -19,7 +19,7 @@ MAKE = make
- # C-preprocessor flags
- CPPFLAGS ?=
- # C-compiler flags
--CFLAGS += -ffast-math -funroll-loops -fPIC -pedantic -Wall
-+CFLAGS += -ffast-math -funroll-loops -fPIC -pedantic -Wall -fcommon
- 
- CC     = gcc 
- #LDLIB  = -ldl

sci-chemistry/xcrysden/xcrysden-1.6.2.ebuild

@@ -3,7 +3,7 @@
 
 EAPI=8
 
-inherit desktop xdg
+inherit desktop flag-o-matic xdg
 
 DESCRIPTION="For the visualisation of molecular and crystal structures."
 
@@ -28,7 +28,6 @@ BDEPEND="${RDEPEND}"
 
 PATCHES=(
 	"${FILESDIR}/${P}-ext-bwidget.patch"
-	"${FILESDIR}/${P}-gcc_flags.patch"
 	"${FILESDIR}/${P}-Togl_lib.patch"
 	"${FILESDIR}/${P}-wrapper_paths.patch"
 )
@@ -39,6 +38,7 @@ src_prepare() {
 }
 
 src_compile() {
+	append-cflags "-fcommon"
 	emake xcrysden
 }