add compat tests for relative jumps with immediate offset from absolute symbol

Values assigned to symbols using .set should be specified in words (not
bytes). Thus, this test ensures that the value of the const symbol is not
converted to words (divided by 4).

Since py-esp32-ulp internally tracks symbol values as words anyway, this
behaviour has been correct all along. The test aims to show that recent
changes related to immediate value handling did not break this (and to
guard against future changes that could break this).

Author: wnienhaus

Diff for: tests/compat/jumps.S

@@ -1,4 +1,6 @@
   .text
+  .set const, 3
+  .global const  # exporting symbol is required for binutils, not important for py-esp32-ulp
 
 entry:
   nop
@@ -27,6 +29,9 @@ entry:
   jumps -8, 42, lt
   jumps -32, 42, lt
 
+  # jumps with immediate offset from absolute symbol
+  jumps const, 42, lt
+
   # jumpr with labels
   jumpr entry, 42, lt
   jumpr later, 42, lt
@@ -50,6 +55,9 @@ entry:
   jumpr -8, 42, lt
   jumpr -32, 42, lt
 
+  # jumps with immediate offset from absolute symbol
+  jumpr const, 42, lt
+
   nop
   nop
   nop