[gdb/testsuite] Remove superfluous pid in temp files

While trying to use gdb_can_simple_compile with a d program, I ran into:
...
/data/vries/gdb/f37/build/gdb/testsuite/temp/105856/can_compile_d-105856.d: \
  error: module 'can_compile_d-105856' has non-identifier characters in \
  filename, use module declaration instead
...

The d compiler has a problem with the filename can_compile_d-105856.d, which
contains the pid.  The pid is added by gdb_simple_compile:
...
    set obj [standard_temp_file $name-[pid].$postfix]
...
but it's unnecessary because standard_temp_file already uses the pid.

Fix this by removing "[pid]" in all calls to standard_temp_file.

Tested on x86_64-linux.
diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp
index 8b0cf77..434495d 100644
--- a/gdb/testsuite/lib/dwarf.exp
+++ b/gdb/testsuite/lib/dwarf.exp
@@ -294,7 +294,7 @@
     }
 
     if { $do_start } {
-	set exe [standard_temp_file func_addr[pid].x]
+	set exe [standard_temp_file func_addr.x]
 
 	gdb_compile $src $exe executable $options
 
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 3cfe22b..f8046ff 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -4579,8 +4579,8 @@
     set me "universal_compile_options"
     set options {}
 
-    set src [standard_temp_file ccopts[pid].c]
-    set obj [standard_temp_file ccopts[pid].o]
+    set src [standard_temp_file ccopts.c]
+    set obj [standard_temp_file ccopts.o]
 
     gdb_produce_source $src {
 	int foo(void) { return 0; }
@@ -4635,8 +4635,8 @@
 	    break
 	}
     }
-    set src [standard_temp_file $name-[pid].$ext]
-    set obj [standard_temp_file $name-[pid].$postfix]
+    set src [standard_temp_file $name.$ext]
+    set obj [standard_temp_file $name.$postfix]
     set compile_flags [concat $compile_flags {debug nowarnings quiet}]
 
     gdb_produce_source $src $code
@@ -7011,8 +7011,8 @@
 
 	# Set up, compile, and execute a test program having VFP
 	# operations.
-	set src [standard_temp_file arm_vfp[pid].c]
-	set exe [standard_temp_file arm_vfp[pid].x]
+	set src [standard_temp_file arm_vfp.c]
+	set exe [standard_temp_file arm_vfp.x]
 
 	gdb_produce_source $src {
 	    int main() {