Restore proper dot symbol creation for assembly files in the kernel build case.

Without this patch we were not able to see the assembly function.
Only the function descriptor was visible.

- Distinguish between user-land and kernel when creating the ENTRY() point of
  assembly source.
- Make the ENTRY() macro more readable, replace the .align directive with the
  gas platform independant .p2align directive.
- Create an END()macro for later use to provide traceback tables on powerpc64.

sys/powerpc/include/asm.h

@@ -61,19 +61,51 @@
 #define	HIDENAME(asmsym)	__CONCAT(.,asmsym)
 #endif
 
-#define	_GLOBAL(x) \
-	.data; .align 2; .globl x; x:
+#ifdef _KERNEL
+#define	DOT_LABEL(name)		__CONCAT(.,name)
+#define	TYPE_ENTRY(name)	.size	name,24; \
+				.type	DOT_LABEL(name),@function; \
+				.globl	DOT_LABEL(name);
+#define	END_SIZE(name)		.size	DOT_LABEL(name),.-DOT_LABEL(name);
+#else /* !_KERNEL */
+#define	DOT_LABEL(name)		__CONCAT(.L.,name)
+#define	TYPE_ENTRY(name)	.type	name,@function;
+#define	END_SIZE(name)		.size	name,.-DOT_LABEL(name);
+#endif /* _KERNEL */
 
-#ifdef __powerpc64__ 
-#define _ENTRY(x) \
-	.text; .align 2; .globl x; .section ".opd","aw"; \
-	.align 3; x: \
-	    .quad .L.x,.TOC.@tocbase,0; .size x,24; .previous; \
-	.align 4; .type x,@function; .L.x:
-#else
-#define	_ENTRY(x) \
-	.text; .align 4; .globl x; .type x,@function; x:
-#endif
+#define	_GLOBAL(name) \
+	.data; \
+	.p2align 2; \
+	.globl	name; \
+	name:
+
+#ifdef __powerpc64__
+#define	_ENTRY(name) \
+	.section ".text"; \
+	.p2align 2; \
+	.globl	name; \
+	.section ".opd","aw"; \
+	.p2align 3; \
+	name: \
+	.quad	DOT_LABEL(name),.TOC.@tocbase,0; \
+	.previous; \
+	.p2align 4; \
+	TYPE_ENTRY(name) \
+DOT_LABEL(name):
+
+#define	_END(name) \
+	.long	0; \
+	.byte	0,0,0,0,0,0,0,0; \
+	END_SIZE(name)
+#else /* !__powerpc64__ */
+#define	_ENTRY(name) \
+	.text; \
+	.p2align 4; \
+	.globl	name; \
+	.type	name,@function; \
+	name:
+#define	_END(name)
+#endif /* __powerpc64__ */
 
 #if defined(PROF) || (defined(_KERNEL) && defined(GPROF))
 # ifdef __powerpc64__
@@ -99,6 +131,7 @@
 #endif
 
 #define	ASENTRY(y)	_ENTRY(ASMNAME(y)); _PROF_PROLOGUE
+#define	END(y)		_END(CNAME(y))
 #define	ENTRY(y)	_ENTRY(CNAME(y)); _PROF_PROLOGUE
 #define	GLOBAL(y)	_GLOBAL(CNAME(y))