gdb/testsuite/gdb.trace: Deduplicate pcreg/spreg/fpreg.

These variables were used in many gdb.trace tests.  Keep them in one place,
to reduce work needed for new targets.

gdb/testsuite/ChangeLog:

	* gdb.trace/backtrace.exp: Use global fpreg/spreg definition, add $
	in front.
	* gdb.trace/change-loc.exp: Use global pcreg definition.
	* gdb.trace/collection.exp: Use global pcreg/fpreg/spreg definition.
	* gdb.trace/entry-values.exp: Use global spreg definition, add $
	in front.
	* gdb.trace/mi-trace-frame-collected.exp: Use global pcreg definition.
	* gdb.trace/pending.exp: Likewise.
	* gdb.trace/report.exp: Use global pcreg/fpreg/spreg definition.
	* gdb.trace/trace-break.exp: Likewise.
	* gdb.trace/trace-condition.exp: Use global pcreg definition, add $
	in front.
	* gdb.trace/unavailable.exp: Use global pcreg/fpreg/spreg definition.
	* gdb.trace/while-dyn.exp: Use global fpreg definition, add $
	in front.
	* lib/trace-support.exp: Define fpreg, spreg, pcreg variables.

1 files changed, 23 insertions, 0 deletions

diff --git a/gdb/testsuite/lib/trace-support.exp b/gdb/testsuite/lib/trace-support.exp
index 0af73b4..4ec8cac 100644
--- a/gdb/testsuite/lib/trace-support.exp
+++ b/gdb/testsuite/lib/trace-support.exp
@@ -20,6 +20,29 @@
 
 
 #
+# Program counter / stack pointer / frame pointer for supported targets.
+# Used in many tests, kept here to avoid duplication.
+#
+
+if [is_amd64_regs_target] {
+    set fpreg "rbp"
+    set spreg "rsp"
+    set pcreg "rip"
+} elseif [is_x86_like_target] {
+    set fpreg "ebp"
+    set spreg "esp"
+    set pcreg "eip"
+} elseif [is_aarch64_target] {
+    set fpreg "x29"
+    set spreg "sp"
+    set pcreg "pc"
+} else {
+    set fpreg "fp"
+    set spreg "sp"
+    set pcreg "pc"
+}
+
+#
 # Procedure: gdb_target_supports_trace
 # Returns true if GDB is connected to a target that supports tracing.
 # Allows tests to abort early if not running on a trace-aware target.