Bump version to 6.4.0 (#14727)

Jo Shields · web-flow · commit da1fa281093e · 2019-05-31T12:53:23.000-04:00
diff --git a/configure.ac b/configure.ac
@@ -4,7 +4,7 @@
 # This line is parsed by tools besides autoconf, such as msvc/mono.winconfig.targets.
 # It should remain in the format they expect.
 #
-AC_INIT(mono, [6.3.0],
+AC_INIT(mono, [6.4.0],
         [https://github.com/mono/mono/issues/new])
 
 AC_CONFIG_SRCDIR([README.md])
diff --git a/external/linker b/external/linker
@@ -1 +1 @@
-Subproject commit a59f4b35a7405395ef22bbf9699c634d7be9939d
+Subproject commit 15b5a5f682a3f3345f473b655d51940bdd8fd1a8

Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@`
`4`	`4`	`# This line is parsed by tools besides autoconf, such as msvc/mono.winconfig.targets.`
`5`	`5`	`# It should remain in the format they expect.`
`6`	`6`	`#`
`7`		`-AC_INIT(mono, [6.3.0],`
	`7`	`+AC_INIT(mono, [6.4.0],`
`8`	`8`	`[https://github.com/mono/mono/issues/new])`
`9`	`9`
`10`	`10`	`AC_CONFIG_SRCDIR([README.md])`