Fix register lifetime for min/max in quants.

Since we backtrack in/out of the quant code, the min/max must not be
kept in registers with a lifetime of just that region of code, or they
may get scribbled over. Fixes the remaining t/qregex failure and one
of the t/p5regex failures.

src/vm/moar/QAST/QASTRegexCompilerMAST.nqp

@@ -540,11 +540,7 @@ class QAST::MASTRegexCompiler {
         my $needmark  := $needrep || $backtrack eq 'r';
         my $rep       := %*REG<rep>;
         my $pos       := %*REG<pos>;
-        my $minreg := fresh_i();
-        my $maxreg := fresh_i();
-        nqp::push(@ins, op('const_i64', $minreg, ival($min))) if $min > 1;
-        nqp::push(@ins, op('const_i64', $maxreg, ival($max))) if $max > 1;
-        my $ireg := fresh_i();
+        my $ireg      := fresh_i();
 
         if $backtrack eq 'f' {
             my $seplabel := label($prefix ~ '_sep');
@@ -564,12 +560,18 @@ class QAST::MASTRegexCompiler {
             nqp::push(@ins, op('set', $rep, $ireg));
             nqp::push(@ins, op('inc_i', $rep));
             if $min > 1 {
+                my $minreg := fresh_i();
+                nqp::push(@ins, op('const_i64', $minreg, ival($min)));
                 nqp::push(@ins, op('lt_i', $ireg, $rep, $minreg));
                 nqp::push(@ins, op('if_i', $ireg, $looplabel));
+                release($minreg, $MVM_reg_int64);
             }
             if $max > 1 {
+                my $maxreg := fresh_i();
+                nqp::push(@ins, op('const_i64', $maxreg, ival($max))) if $max > 1;
                 nqp::push(@ins, op('ge_i', $ireg, $rep, $maxreg));
                 nqp::push(@ins, op('if_i', $ireg, $donelabel));
+                release($maxreg, $MVM_reg_int64);
             }
             self.regex_mark(@ins, $looplabel_index, $pos, $rep) if $max != 1;
             nqp::push(@ins, $donelabel);
@@ -584,8 +586,11 @@ class QAST::MASTRegexCompiler {
                 self.regex_commit(@ins, $donelabel_index) if $backtrack eq 'r';
                 nqp::push(@ins, op('inc_i', $rep));
                 if $max > 1 {
+                    my $maxreg := fresh_i();
+                    nqp::push(@ins, op('const_i64', $maxreg, ival($max))) if $max > 1;
                     nqp::push(@ins, op('ge_i', $ireg, $rep, $maxreg));
                     nqp::push(@ins, op('if_i', $ireg, $donelabel));
+                    release($maxreg, $MVM_reg_int64);
                 }
             }
             unless $max == 1 {
@@ -595,13 +600,14 @@ class QAST::MASTRegexCompiler {
             }
             nqp::push(@ins, $donelabel);
             if $min > 1 {
+                my $minreg := fresh_i();
+                nqp::push(@ins, op('const_i64', $minreg, ival($min)));
                 nqp::push(@ins, op('lt_i', $ireg, $rep, $minreg));
                 nqp::push(@ins, op('if_i', $ireg, %*REG<fail>));
+                release($minreg, $MVM_reg_int64);
             }
         }
         release($ireg, $MVM_reg_int64);
-        release($minreg, $MVM_reg_int64);
-        release($maxreg, $MVM_reg_int64);
         @ins
     }