Eliminate crash in matching of utf32 segment

Author: bjorng

erts/emulator/beam/emu/ops.tab

@@ -1233,6 +1233,11 @@ bs_skip_utf16 Fail=f Ms=xy Unit=u Flags=u => bs_get_utf16 Fail Ms Unit Flags x
 
 i_bs_get_utf16 xy f? t d
 
+bs_get_utf32 Fail=f Ms=xy Live=u Flags=u Dst | equal(Ms, Dst) =>
+    bs_get_integer2 Fail Ms Live i=32 u=1 Flags x |
+    i_bs_validate_unicode_retract Fail x Ms |
+    move x Dst
+
 bs_get_utf32 Fail=f Ms=xy Live=u Flags=u Dst=d =>
     bs_get_integer2 Fail Ms Live i=32 u=1 Flags Dst |
     i_bs_validate_unicode_retract Fail Dst Ms

erts/emulator/beam/jit/arm/ops.tab

@@ -951,6 +951,10 @@ bs_skip_utf16 Fail=f Ms=xy u Flags=u => skip_utf16(Fail, Ms, Flags)
 i_bs_get_utf16 S f t d
 i_bs_skip_utf16 S f t
 
+bs_get_utf32 Fail=f Ms=xy Live=u Flags=u Dst | equal(Ms, Dst) =>
+    bs_get_integer2 Fail Ms Live i=32 u=1 Flags x |
+    i_bs_validate_unicode_retract Fail x Ms |
+    move x Dst
 bs_get_utf32 Fail=f Ms=xy Live=u Flags=u Dst=d =>
     bs_get_integer2 Fail Ms Live i=32 u=1 Flags Dst |
     i_bs_validate_unicode_retract Fail Dst Ms

erts/emulator/beam/jit/x86/ops.tab

@@ -923,6 +923,11 @@ bs_skip_utf16 Fail=f Ms=xy u Flags=u => skip_utf16(Fail, Ms, Flags)
 i_bs_get_utf16 S f t d
 i_bs_skip_utf16 S f t
 
+bs_get_utf32 Fail=f Ms=xy Live=u Flags=u Dst | equal(Ms, Dst) =>
+    bs_get_integer2 Fail Ms Live i=32 u=1 Flags x |
+    i_bs_validate_unicode_retract Fail x Ms |
+    move x Dst
+
 bs_get_utf32 Fail=f Ms=xy Live=u Flags=u Dst=d =>
     bs_get_integer2 Fail Ms Live i=32 u=1 Flags Dst |
     i_bs_validate_unicode_retract Fail Dst Ms

erts/emulator/test/bs_utf_SUITE.erl

@@ -272,6 +272,10 @@ utf32_illegal_sequences(Config) when is_list(Config) ->
     utf32_fail_range(16#10FFFF+1, 16#10FFFF+512), %Too large.
     utf32_fail_range(16#D800, 16#DFFF),		%Reserved for UTF-16.
     utf32_fail_range(-100, -1),
+
+    <<>> = id(<< 0 || <<X/utf32>> <= <<"àxxx">>, _ = X >>),
+    <<>> = id(<< 0 || <<X/little-utf32>> <= <<"àxxx">>, _ = X >>),
+
     ok.
 
 utf32_fail_range(Char, End) when Char =< End ->