gcc: default the Vita target to local-exec TLS

Design phase 1 says the main executable uses Local Exec, but nothing enforced
it: for a TLS symbol defined in another translation unit gcc falls back to
initial-exec, which wants a GOT entry the Vita loader never fills. Linking a
newlib with its reent in TLS produced 36 R_ARM_TLS_IE32 against _tls_errno
plus 15 R_ARM_TLS_LDO32, and vita-elf-create refused them.

CC1_SPEC only supplies the default, so -ftls-model= on the command line still
wins.

Assisted-by: Claude Opus 5

Author: frangarcj

patches/gcc/0001-vita-target.patch

@@ -15,7 +15,19 @@ diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
 index 30e1d6dc9..bd5f7b19c 100644
 --- a/gcc/config/arm/arm.h
 +++ b/gcc/config/arm/arm.h
-@@ -731,6 +731,10 @@ extern const int arm_arch_cde_coproc_bits[];
+@@ -87,8 +87,10 @@ extern tree arm_bf16_ptr_type_node;
+ #undef  CPP_SPEC
+ #define CPP_SPEC "%(subtarget_cpp_spec)"
+ 
+ #ifndef CC1_SPEC
+-#define CC1_SPEC ""
++/* The loader hands each thread its TLS block at a fixed offset from
++   TPIDRURO; every model but local-exec wants a GOT it never fills.  */
++#define CC1_SPEC "%{!ftls-model=*:-ftls-model=local-exec}"
+ #endif
+ 
+ /* This macro defines names of additional specifications to put in the specs
+@@ -731,6 +733,10 @@ extern const int arm_arch_cde_coproc_bits[];
  #define WCHAR_TYPE_SIZE BITS_PER_WORD
  #endif
 
@@ -26,7 +38,7 @@ index 30e1d6dc9..bd5f7b19c 100644
  /* Sized for fixed-point types.  */
 
  #define SHORT_FRACT_TYPE_SIZE 8
-@@ -1996,7 +2000,7 @@ enum arm_auto_incmodes
+@@ -1996,7 +2002,7 @@ enum arm_auto_incmodes
  /* signed 'char' is most compatible, but RISC OS wants it unsigned.
     unsigned is probably best, but may break some code.  */
  #ifndef DEFAULT_SIGNED_CHAR