libc/riscv: fix link errors with GCC 12

Dynamically linked functions can not be called directly with jump ("j",
"jal") and friends. Calls must go through the PLT.

issue #4827

repos/libports/ports/libc.hash

@@ -1 +1 @@
-a4d148016cfbc4c494b277e164d67617cf540e31
+dfcf0321f6f20fb8051954bc3fb4e661467a3434

repos/libports/src/lib/libc/patches/sigsetjmp_riscv.patch

@@ -0,0 +1,40 @@
+Back port from FreeBSD 13.1. required for GCC 12
+
+Fixes ld error message: "relocation R_RISCV_JAL against `setjmp' which may bind
+externally can not be used when making a shared object" which means that there
+can not be a direct jump ("j", "jal", etc.) to a function is a jump slot (in
+PLT). So do not use the "j" calls.
+
+--- src/lib/libc/lib/libc/riscv/gen/sigsetjmp.S
++++ src/lib/libc/lib/libc/riscv/gen/sigsetjmp.S
+@@ -38,20 +38,24 @@ __FBSDID("$FreeBSD: releng/12.0/lib/libc/riscv/gen/sigsetjmp.S 294227 2016-01-17
+ #include <machine/setjmp.h>
+ 
+ ENTRY(sigsetjmp)
+-	beqz	a1, _C_LABEL(_setjmp)
+-	j	_C_LABEL(setjmp)
++	beqz	a1, 1f
++tail	_C_LABEL(setjmp)
++	1:
++	tail	_C_LABEL(_setjmp)
+ END(sigsetjmp)
+ 
+ ENTRY(siglongjmp)
+ 	/* Load the _setjmp magic */
+ 	ld	a2, .Lmagic
+-	ld	a3, 0(a0)
++ld	a3, 0(a0)
+ 
+ 	/* Check the magic */
+-	beq	a2, a3, _C_LABEL(_longjmp)
+-	j	_C_LABEL(longjmp)
++	beq	a2, a3, 1f
++tail	_C_LABEL(longjmp)
++	1:
++tail	_C_LABEL(_longjmp)
+ 
+ 	.align	3
+-.Lmagic:
++	.Lmagic:
+ 	.quad	_JB_MAGIC__SETJMP
+ END(siglongjmp)