AArch64: Reformat inline-asm in elf_machine_load_address

This patch reformats the inline-asm in elf_machine_load_address so it is
easier to change only part of the inline-asm.  That is using string
concatenating instead of string continuation.

Also document why this inline-asm works - it depends on the 32bit
relocation being resolved at link time.

ChangeLog:

2014-11-21  Will Newton  <will.newton@linaro.org>
	    Andrew Pinski  <andrew.pinski@caviumnetworks.com>

	* sysdeps/aarch64/dl-machine.h (elf_machine_load_address):
	Refactor inline-asm.  Also add comment.

ChangeLog

@@ -1,6 +1,9 @@
 2014-11-21  Will Newton  <will.newton@linaro.org>
 	    Andrew Pinski  <andrew.pinski@caviumnetworks.com>
 
+	* sysdeps/aarch64/dl-machine.h (elf_machine_load_address):
+	Refactor inline-asm.  Also add comment.
+
 	* sysdeps/aarch64/bits/link.h (la_aarch64_gnu_pltenter): Use
 	ElfW macro instead of hardcoded Elf64 types.
 	(la_aarch64_gnu_pltenter): Likewise.

sysdeps/aarch64/dl-machine.h

@@ -52,19 +52,22 @@ elf_machine_load_address (void)
      The choice of symbol is arbitrary. The static address we obtain
      by constructing a non GOT reference to the symbol, the dynamic
      address of the symbol we compute using adrp/add to compute the
-     symbol's address relative to the PC. */
+     symbol's address relative to the PC.
+     This depends on 32bit relocations being resolved at link time
+     and that the static address fits in the 32bits.  */
 
   ElfW(Addr) static_addr;
   ElfW(Addr) dynamic_addr;
 
-  asm ("					\n\
-	adrp	%1, _dl_start;			\n\
-        add	%1, %1, #:lo12:_dl_start        \n\
-        ldr	%w0, 1f				\n\
-	b	2f				\n\
-1:	.word	_dl_start			\n\
-2:						\n\
-       " : "=r" (static_addr),  "=r" (dynamic_addr));
+  asm ("					\n"
+"	adrp	%1, _dl_start;			\n"
+"	add	%1, %1, #:lo12:_dl_start	\n"
+"	ldr	%w0, 1f				\n"
+"	b	2f				\n"
+"1:						\n"
+"	.word	_dl_start			\n"
+"2:						\n"
+    : "=r" (static_addr),  "=r" (dynamic_addr));
   return dynamic_addr - static_addr;
 }