arm: Fix PCS for SFmode -> SImode libcalls [PR99748]

This patch fixes PR99748 which shows us trying to pass the argument to
__aeabi_f2iz in the VFP register s0 when the library function is
expecting to use the GPR r0. It also fixes the __aeabi_f2uiz case which
was broken in the same way.

For the testcase in the PR, here is the code we generate before the
patch (with -mfloat-abi=hard -march=armv8.1-m.main+mve -O0):

main:
    push    {r7, lr}
    sub     sp, sp, gcc-mirror#8
    add     r7, sp, #0
    mov     r3, #1065353216
    str     r3, [r7, gcc-mirror#4]    @ float
    vldr.32 s0, [r7, gcc-mirror#4]
    bl      __aeabi_f2iz
    mov     r3, r0
    cmp     r3, #1
    [...]

This becomes:

main:
    push    {r7, lr}
    sub     sp, sp, gcc-mirror#8
    add     r7, sp, #0
    mov     r3, #1065353216
    str     r3, [r7, gcc-mirror#4]    @ float
    ldr     r0, [r7, gcc-mirror#4]    @ float
    bl      __aeabi_f2iz
    mov     r3, r0
    cmp     r3, #1
    [...]

after the patch. We see a similar change for the same testcase with a
cast to unsigned instead of int.

gcc/ChangeLog:

	PR target/99748
	* config/arm/arm.c (arm_libcall_uses_aapcs_base): Also use base
	PCS for [su]fix_optab.

(cherry picked from commit 16ea7f5)

Author: acoplan-arm

gcc/config/arm/arm.c

@@ -5786,6 +5786,10 @@ arm_libcall_uses_aapcs_base (const_rtx libcall)
 		   convert_optab_libfunc (sfix_optab, DImode, SFmode));
       add_libcall (libcall_htab,
 		   convert_optab_libfunc (ufix_optab, DImode, SFmode));
+      add_libcall (libcall_htab,
+		   convert_optab_libfunc (sfix_optab, SImode, SFmode));
+      add_libcall (libcall_htab,
+		   convert_optab_libfunc (ufix_optab, SImode, SFmode));
 
       /* Values from double-precision helper functions are returned in core
 	 registers if the selected core only supports single-precision