makepkg: Add support for specifying LDFLAGS

Provide support for specifying LDFLAGS within makepkg.conf but leaves
this undefined by default. Fixes FS#12542.

Signed-off-by: Allan McRae <allan@archlinux.org>
Signed-off-by: Dan McGee <dan@archlinux.org>

doc/makepkg.conf.5.txt

@@ -61,6 +61,11 @@ Options
 **CXXFLAGS=**"cxxflags"::
 	Flags used for the C++ compiler; see CFLAGS for more info.
 
+**LDFLAGS=**"ldflags"::
+	Flags used for the linker. Several options may be specified with common
+	usage resembling ``-Wl,--hash-style=gnu``. Read ld(1) for more details on
+	available linker flags.
+
 **MAKEFLAGS=**"makeflags"::
 	This is often used to set the number of jobs used, for example, `-j2`.
 	Other flags that make accepts can also be passed.

etc/makepkg.conf.in

@@ -31,6 +31,7 @@ CHOST="@CHOST@"
 # -mtune optimizes for an architecture, but builds for whole processor family
 CFLAGS="@CARCHFLAGS@-mtune=generic -O2 -pipe"
 CXXFLAGS="@CARCHFLAGS@-mtune=generic -O2 -pipe"
+#LDFLAGS=""
 #-- Make Flags: change this for DistCC/SMP systems
 #MAKEFLAGS="-j2"
 

scripts/makepkg.sh.in

@@ -674,7 +674,7 @@ run_build() {
 	cd "$srcdir"
 
 	# ensure all necessary build variables are exported
-	export CFLAGS CXXFLAGS MAKEFLAGS CHOST
+	export CFLAGS CXXFLAGS MAKEFLAGS LDFLAGS CHOST
 	# save our shell options so build() can't override what we need
 	local shellopts=$(shopt -p)