struct variable behind guard, proper macro check, and remove some whitespace.

Wrap runtime_main as per its declaration in tcc.h.
Fix preprocessor check for TCC_ARM_EABI macro definition.

Signed-off-by: Joseph Poirier <jdpoirier@gmail.com>

arm-gen.c

@@ -802,7 +802,7 @@ int assign_fpreg(struct avail_regs *avregs, int align, int size)
 
 /* Return 1 if this function returns via an sret pointer, 0 otherwise */
 ST_FUNC int gfunc_sret(CType *vt, CType *ret, int *ret_align) {
-#if TCC_ARM_EABI
+#ifdef TCC_ARM_EABI
     int size, align;
     size = type_size(vt, &align);
     if (size > 4) {

libtcc.c

@@ -1026,7 +1026,9 @@ LIBTCCAPI TCCState *tcc_new(void)
 #ifdef TCC_TARGET_I386
     s->seg_size = 32;
 #endif
+#ifdef TCC_IS_NATIVE
     s->runtime_main = "main";
+#endif
     return s;
 }