Fix some libc functions crashing

[apaillier-ledger]

Description

Was noticed and worked around in some apps like there.

Here is newlib's strcasecmp in various configurations :

• Right now built with GCC (12.2.1) :

00000000 <strcasecmp>:
       0: b530          push    {r4, r5, lr}
       2: 4604          mov     r4, r0
       4: 4d0c          ldr     r5, [pc, #0x30]         @ 0x38 <strcasecmp+0x38>
       6: f814 3b01     ldrb    r3, [r4], #1
       a: 5cea          ldrb    r2, [r5, r3]
       c: f002 0203     and     r2, r2, #0x3
      10: 2a01          cmp     r2, #0x1
      12: f811 2b01     ldrb    r2, [r1], #1
      16: bf08          it      eq
      18: 3320          addeq   r3, #0x20
      1a: 5ca8          ldrb    r0, [r5, r2]
      1c: f000 0003     and     r0, r0, #0x3
      20: 2801          cmp     r0, #0x1
      22: d103          bne     0x2c <strcasecmp+0x2c>  @ imm = #0x6
      24: 3220          adds    r2, #0x20
      26: 1a98          subs    r0, r3, r2
      28: d0ed          beq     0x6 <strcasecmp+0x6>    @ imm = #-0x26
      2a: bd30          pop     {r4, r5, pc}
      2c: 1a98          subs    r0, r3, r2
      2e: d1fc          bne     0x2a <strcasecmp+0x2a>  @ imm = #-0x8
      30: 2a00          cmp     r2, #0x0
      32: d1e8          bne     0x6 <strcasecmp+0x6>    @ imm = #-0x30
      34: e7f9          b       0x2a <strcasecmp+0x2a>  @ imm = #-0xe
      36: bf00          nop
      38: 01 00 00 00   .word   0x00000001

• Built with clang (19.1.7) :

00000000 <strcasecmp>:
       0: b5d0          push    {r4, r6, r7, lr}
       2: af02          add     r7, sp, #0x8
       4: f240 0200     movw    r2, #0x0
       8: f2c0 0200     movt    r2, #0x0
       c: f102 0c01     add.w   r12, r2, #0x1
      10: f810 4b01     ldrb    r4, [r0], #1
      14: f81c 2004     ldrb.w  r2, [r12, r4]
      18: f002 0e03     and     lr, r2, #0x3
      1c: f811 2b01     ldrb    r2, [r1], #1
      20: f1be 0f01     cmp.w   lr, #0x1
      24: f81c e002     ldrb.w  lr, [r12, r2]
      28: bf08          it      eq
      2a: 3420          addeq   r4, #0x20
      2c: f00e 0303     and     r3, lr, #0x3
      30: 2b01          cmp     r3, #0x1
      32: bf08          it      eq
      34: 3220          addeq   r2, #0x20
      36: 4294          cmp     r4, r2
      38: d101          bne     0x3e <strcasecmp+0x3e>  @ imm = #0x2
      3a: 2a00          cmp     r2, #0x0
      3c: d1e8          bne     0x10 <strcasecmp+0x10>  @ imm = #-0x30
      3e: 1aa0          subs    r0, r4, r2
      40: bdd0          pop     {r4, r6, r7, pc}

• Built with clang (19.1.7) and the -fropi -frwpi flags :

00000000 <strcasecmp>:
       0: b5d0          push    {r4, r6, r7, lr}
       2: af02          add     r7, sp, #0x8
       4: f64f 72f4     movw    r2, #0xfff4
       8: f6cf 72f8     movt    r2, #0xfff8
       c: 447a          add     r2, pc
       e: f102 0c01     add.w   r12, r2, #0x1
      12: bf00          nop
      14: f810 4b01     ldrb    r4, [r0], #1
      18: f81c 2004     ldrb.w  r2, [r12, r4]
      1c: f002 0e03     and     lr, r2, #0x3
      20: f811 2b01     ldrb    r2, [r1], #1
      24: f1be 0f01     cmp.w   lr, #0x1
      28: f81c e002     ldrb.w  lr, [r12, r2]
      2c: bf08          it      eq
      2e: 3420          addeq   r4, #0x20
      30: f00e 0303     and     r3, lr, #0x3
      34: 2b01          cmp     r3, #0x1
      36: bf08          it      eq
      38: 3220          addeq   r2, #0x20
      3a: 4294          cmp     r4, r2
      3c: d101          bne     0x42 <strcasecmp+0x42>  @ imm = #0x2
      3e: 2a00          cmp     r2, #0x0
      40: d1e8          bne     0x14 <strcasecmp+0x14>  @ imm = #-0x30
      42: 1aa0          subs    r0, r4, r2
      44: bdd0          pop     {r4, r6, r7, pc}

As noted by the wise @0pendev here, LLVM 19 is required as newlib can't be built with clang 14 currently used with the app-builder docker containers, so we'll probably wait for their migration to Debian 13 that comes with it by default. 🚨
And also libgloss has issues being built by something other than GCC, so it has been disabled as well.

Changes include

• Bugfix (non-breaking change that solves an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)
• Tests
• Documentation
• Other (for changes that might not fit in any category)

Auto cherry-pick in API_LEVEL

[x] TARGET_API_LEVEL: API_LEVEL_25

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.60%. Comparing base (5508407) to head (ca1c27d).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1351   +/-   ##
=======================================
  Coverage   78.60%   78.60%           
=======================================
  Files          42       42           
  Lines        4571     4571           
  Branches      669      669           
=======================================
  Hits         3593     3593           
  Misses        928      928           
  Partials       50       50           

Flag	Coverage Δ
unittests	78.60% <ø> (ø)

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[iartemov-ledger]

Cool @apaillier-ledger !
Do the both clang compilations (with and without -fropi -frwpi flags) resolve ldr r5, [pc, #0x30] @ 0x38 <strcasecmp+0x38> issue - i.e. an attempt to read an external global array ?