[fix](be) Preserve Bash 3 and UBSan compatibility

### What problem does this PR solve?

Issue Number: None

Related PR: #66857

Problem Summary: The ARM hardening changes used Bash 4 lowercase expansion in the third-party build, which breaks the Bash 3.2 shipped by supported macOS runners. The bit-packing alignment fix also left the whole unpack function excluded from undefined-behavior sanitization, so the new alignment regression test could not detect a reintroduced misaligned dereference. Use Bash 3-compatible case patterns and restore UBSan instrumentation now that all word reads use memcpy-based unaligned_load.

### Release note

None

### Check List (For Author)

- Test: Unit Test / Manual test
    - Bash syntax and extracted boolean case matrix
    - BE build hygiene and diff checks
    - Clang 19 alignment-sanitized BitPackingUnalignedTest (1/1 passed)
- Behavior changed: No (restores supported build compatibility and sanitizer coverage)
- Does this need documentation: No

Author: u70b3

be/src/util/bit_packing.inline.h

@@ -193,7 +193,7 @@ std::pair<const uint8_t*, int64_t> BitPacking::UnpackAndDecodeValues(
 // avoid buffer overflow (if we are unpacking 32 values, we can safely assume an input
 // buffer of length 32 * BIT_WIDTH).
 template <int BIT_WIDTH, int VALUE_IDX, bool FULL_BATCH>
-uint64_t NO_SANITIZE_UNDEFINED UnpackValue(const uint8_t* __restrict__ in_buf) {
+uint64_t UnpackValue(const uint8_t* __restrict__ in_buf) {
     if (BIT_WIDTH == 0) return 0;
 
     constexpr int FIRST_BIT_IDX = VALUE_IDX * BIT_WIDTH;

thirdparty/build-thirdparty.sh

@@ -1404,18 +1404,18 @@ build_bitshuffle() {
 # croaring bitmap
 build_croaringbitmap() {
     avx_flag=''
-    # USE_AVX2 accepts the same boolean spellings as CMake, case-insensitively:
+    # USE_AVX2 accepts common CMake boolean spellings, case-insensitively:
     # 0/OFF/FALSE/NO disable AVX2, 1/ON/TRUE/YES or empty/unset keep it enabled.
     # build.sh defaults USE_AVX2=ON and forwards it verbatim to BE's CMake, so
     # croaring must agree with BE on whether AVX2 is enabled. String matching is
     # used instead of `-eq`: in bash arithmetic context the string "ON"
     # evaluates to 0, so exporting USE_AVX2=ON would silently DISABLE AVX2.
-    case "${USE_AVX2,,}" in
-    0 | off | false | no)
+    case "${USE_AVX2}" in
+    0 | [oO][fF][fF] | [fF][aA][lL][sS][eE] | [nN][oO])
         echo "set USE_AVX2=${USE_AVX2} to FORCE disable AVX2 in croaringbitmap"
         avx_flag="-DROARING_DISABLE_AVX=ON"
         ;;
-    1 | on | true | yes | '') ;;
+    1 | [oO][nN] | [tT][rR][uU][eE] | [yY][eE][sS] | '') ;;
     *)
         echo "WARNING: unrecognized USE_AVX2=${USE_AVX2}, AVX2 is left enabled in croaringbitmap"
         ;;