[RISC-V][PR target/118934] Fix ICE in RISC-V long branch support

I'm not sure if I goof'd this or if I merely upstreamed someone else's goof.
Either way the long branch code isn't working correctly.

We were using 'n' as the output modifier to negate the condition.  But 'n' has
a special meaning elsewhere, so when presented with a condition rather than
what was expected, boom, the compiler ICE'd.

Thankfully there's only a few places where we were using %n which I turned into
%r.

The BZ entry includes a good testcase, it just takes a long time to compile as
it's trying to create the out-of-range scenario.  I'm not including the
testcase due to how long it takes, but I did test it locally to ensure it's
working properly now.

I'm sure that with a little bit of work I could create at testcase that worked
before and fails with the trunk (by taking advantage of the fuzzyness in length
computations).  So I'm going to consider this a regression.

Will push to the trunk after pre-commit testing does its thing.

	PR target/118934
gcc/
	* config/riscv/corev.md (cv_branch): Adjust output template.
	(branch): Likewise.
	* config/riscv/riscv.md (branch): Likewise.
	* config/riscv/riscv.cc (riscv_asm_output_opcode): Handle 'r' rather
	than 'n'.

Author: JeffreyALaw

gcc/config/riscv/corev.md

@@ -2627,7 +2627,7 @@
   "TARGET_XCVBI"
 {
   if (get_attr_length (insn) == 12)
-    return "cv.b%n1\t%2,%z3,1f; jump\t%l0,ra; 1:";
+    return "cv.b%r1\t%2,%z3,1f; jump\t%l0,ra; 1:";
 
   return "cv.b%C1imm\t%2,%3,%0";
 }
@@ -2645,7 +2645,7 @@
   "TARGET_XCVBI"
 {
   if (get_attr_length (insn) == 12)
-    return "b%n1\t%2,%z3,1f; jump\t%l0,ra; 1:";
+    return "b%r1\t%2,%z3,1f; jump\t%l0,ra; 1:";
 
   return "b%C1\t%2,%z3,%l0";
 }

gcc/config/riscv/riscv.cc

@@ -6868,7 +6868,7 @@ riscv_asm_output_opcode (FILE *asm_out_file, const char *p)
 	  any outermost HIGH.
    'R'	Print the low-part relocation associated with OP.
    'C'	Print the integer branch condition for comparison OP.
-   'n'	Print the inverse of the integer branch condition for comparison OP.
+   'r'	Print the inverse of the integer branch condition for comparison OP.
    'A'	Print the atomic operation suffix for memory model OP.
    'I'	Print the LR suffix for memory model OP.
    'J'	Print the SC suffix for memory model OP.
@@ -7027,7 +7027,7 @@ riscv_print_operand (FILE *file, rtx op, int letter)
       fputs (GET_RTX_NAME (code), file);
       break;
 
-    case 'n':
+    case 'r':
       /* The RTL names match the instruction names. */
       fputs (GET_RTX_NAME (reverse_condition (code)), file);
       break;

gcc/config/riscv/riscv.md

@@ -3252,7 +3252,7 @@
   "!TARGET_XCVBI"
 {
   if (get_attr_length (insn) == 12)
-    return "b%n1\t%2,%z3,1f; jump\t%l0,ra; 1:";
+    return "b%r1\t%2,%z3,1f; jump\t%l0,ra; 1:";
 
   return "b%C1\t%2,%z3,%l0";
 }