Fix a problem with compilation options being sometimes ignored

when generating PCH. When an action generated two targets, target
variables must be set on both, on just on the first one.
Patch from Franz Schnyder.

	tools/
	* msvc.jam (compile.c++): Call get-rspline on all 'targets',
	to implicitly verify there's just one element.
	(compile.c.pch): Call get-rspline on all targets.
	(compile.c++.pch): Likewise.


[SVN r35605]

v2/tools/msvc.jam

@@ -691,7 +691,7 @@ rule compile.c ( targets + : sources * : properties * )
 
 rule compile.c++ ( targets + : sources * : properties * )
 {
-    get-rspline $(targets[1]) : -TP ;
+    get-rspline $(targets) : -TP ;
     compile-c-c++ $(<) : $(>) [ on $(<) return $(PCH_FILE) ] [ on $(<) return $(PCH_HEADER) ] ;
 }
 
@@ -705,6 +705,7 @@ rule compile.c.pch ( targets + : sources * : properties * )
     C++FLAGS on $(targets[1]) = ;
     DEPENDS $(<) : [ on $(<) return $(PCH_SOURCE) ] ;
     get-rspline $(targets[1]) : -TC ;
+    get-rspline $(targets[2]) : -TC ;
     compile-c-c++-pch $(targets) : $(sources) [ on $(<) return $(PCH_SOURCE) ] ;
 }
 
@@ -712,6 +713,7 @@ rule compile.c++.pch ( targets + : sources * : properties * )
 {
     DEPENDS $(<) : [ on $(<) return $(PCH_SOURCE) ] ;
     get-rspline $(targets[1]) : -TP ;
+    get-rspline $(targets[2]) : -TP ;    
     compile-c-c++-pch $(targets) : $(sources) [ on $(<) return $(PCH_SOURCE) ] ;
 }