package/double-conversion: new package

Both the target and host variants of this package will be needed by
qt6base.

Our reading of double-conversion/utils.h in the code base seems to
show that all architectures currently supported in Buildroot (to the
exception of csky, which we intend to remove, and is anyway not
usable/testable today) are supported by double-conversion.

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

DEVELOPERS

@@ -2327,6 +2327,7 @@ F:	package/bcm2835/
 F:	package/ddrescue/
 F:	package/dejavu/
 F:	package/dillo/
+F:	package/double-conversion/
 F:	package/edid-decode/
 F:	package/ell/
 F:	package/ghostscript-fonts/
@@ -2838,6 +2839,7 @@ F:	package/cloop/
 F:	package/cmake/
 F:	package/cramfs/
 F:	package/dmidecode/
+F:	package/double-conversion/
 F:	package/flashrom/
 F:	package/gcc/
 F:	package/genext2fs/

package/Config.in

@@ -1953,6 +1953,7 @@ menu "Other"
 	source "package/cracklib/Config.in"
 	source "package/dawgdic/Config.in"
 	source "package/ding-libs/Config.in"
+	source "package/double-conversion/Config.in"
 	source "package/eigen/Config.in"
 	source "package/elfutils/Config.in"
 	source "package/ell/Config.in"

package/double-conversion/Config.in

@@ -0,0 +1,11 @@
+config BR2_PACKAGE_DOUBLE_CONVERSION
+	bool "double-conversion"
+	depends on BR2_INSTALL_LIBSTDCPP
+	help
+	  Provides binary-decimal and decimal-binary routines for
+	  IEEE doubles.
+
+	  https://github.com/google/double-conversion
+
+comment "double-conversion needs a toolchain w/ C++"
+	depends on !BR2_INSTALL_LIBSTDCPP

package/double-conversion/double-conversion.hash

@@ -0,0 +1,3 @@
+# Locally computed:
+sha256  3dbcdf186ad092a8b71228a5962009b5c96abde9a315257a3452eb988414ea3b  double-conversion-3.2.0.tar.gz
+sha256  4af93c12062c58058378de2397dc1c92bbff9ddfb1d583a01c84127557ce97ca  COPYING

package/double-conversion/double-conversion.mk

@@ -0,0 +1,14 @@
+################################################################################
+#
+# double-conversion
+#
+################################################################################
+
+DOUBLE_CONVERSION_VERSION = 3.2.0
+DOUBLE_CONVERSION_SITE = $(call github,google,double-conversion,v$(DOUBLE_CONVERSION_VERSION))
+DOUBLE_CONVERSION_LICENSE = BSD-3-Clause
+DOUBLE_CONVERSION_LICENSE_FILES = COPYING
+DOUBLE_CONVERSION_INSTALL_STAGING = YES
+
+$(eval $(cmake-package))
+$(eval $(host-cmake-package))