esp32s2: fix negative immediate offset handling for relative jumps (jumpr, jumps)

When providing negative immediate offset (step) values to the JUMPR and
JUMPS opcodes, the resulting instruction contained an incorrect offset.

This commit fixes that behaviour.

This is the same issue that affected the ESP32 code. See previous commit for
more technical detail on the issue.

Author: wnienhaus

gas/testsuite/gas/esp32ulp/esp32s2/compare/esp32s2ulp_jump.bin

@@ -101,3 +101,18 @@ ESP32ULP GAS  ./gas/testsuite/gas/esp32ulp/esp32s2/esp32s2ulp_jump.s 			page 1
   83 0118 00800388 	    jumps 0x0, 0x00, GE
   84              	
   85              	    
+  86              	    //jumpr with negative offset
+  87 011c 00000682 	    jumpr -0x4, 0x00, EQ
+  88 0120 00000482 	    jumpr -0x4, 0x00, LT
+  89 0124 00000582 	    jumpr -0x4, 0x00, GT
+  90 0128 00000482 	    jumpr -0x4, 0x00, LE
+  90      00000A82 
+  91 0130 00000582 	    jumpr -0x4, 0x00, GE
+  91      00000A82 
+  92              	
+  93              	    //jumps with negative offset
+  94 0138 0000128A 	    jumps -0x4, 0x00, EQ
+  95 013c 0080108A 	    jumps -0x4, 0x00, LT
+  96 0140 0080118A 	    jumps -0x4, 0x00, GT
+  97 0144 0080128A 	    jumps -0x4, 0x00, LE
+  98 0148 0080138A 	    jumps -0x4, 0x00, GE

gas/testsuite/gas/esp32ulp/esp32s2/compare/esp32s2ulp_jump.lst

@@ -83,3 +83,16 @@ jmp2:   nop
     jumps 0x0, 0x00, GE
 
 
+    //jumpr with negative offset
+    jumpr -0x4, 0x00, EQ
+    jumpr -0x4, 0x00, LT
+    jumpr -0x4, 0x00, GT
+    jumpr -0x4, 0x00, LE
+    jumpr -0x4, 0x00, GE
+
+    //jumps with negative offset
+    jumps -0x4, 0x00, EQ
+    jumps -0x4, 0x00, LT
+    jumps -0x4, 0x00, GT
+    jumps -0x4, 0x00, LE
+    jumps -0x4, 0x00, GE

gas/testsuite/gas/esp32ulp/esp32s2/esp32s2ulp_jump.s

@@ -135,7 +135,7 @@ typedef struct {
 #define I_JUMP_RELR(thresh, jud, stp) { *(unsigned int*)&(jump_alu_relr ){ \
     .threshold = thresh, \
     .judge = jud, \
-    .step = stp, \
+    .step = ((stp < 0) ? ((-stp) | (1 << 7)) : stp) , \
     .sub_opcode = SUB_OPCODE_BR, \
     .opcode = OPCODE_BRANCH } }
 
@@ -155,7 +155,7 @@ typedef struct {
     .threshold = thresh, \
 	.unused = 0, \
     .judge = jud, \
-    .step = stp, \
+    .step = ((stp < 0) ? ((-stp) | (1 << 7)) : stp) , \
     .sub_opcode = SUB_OPCODE_BS, \
     .opcode = OPCODE_BRANCH } }