Don't assume pragma directives are a single word

pragma->tail is described as "anything after the operation", but
existing parsing passed just the first whitespace-delimited
word. Change the parsing to just strip leading and trailing
white space off the rest of the line, but keep interior spaces
if there are any.

This is preparation for a build_version pragma for Mach-O matching
the llvm-as .build_version syntax.

Signed-off-by: Fabian Giesen <fabian.giesen@epicgames.com>

Author: Fabian Giesen

asm/pragma.c

@@ -242,7 +242,16 @@ void process_pragma(char *str)
     else
         pragma.opcode = directive_find(pragma.opname);
 
-    pragma.tail = nasm_trim_spaces(p);
+    /*
+     * This used to use nasm_trim_spaces, but that assumes a single word.
+     * Instead, strip spaces at either end of the directive, but allow
+     * interior spaces.
+     */
+    p = nasm_zap_spaces_fwd(p);
+    pragma.tail = p;
+    p += strlen(p);
+    while (p > pragma.tail && nasm_isspace(p[-1]))
+	*--p = 0;
 
     /*
      * Search the global pragma namespaces. This is done