[gdb/testsuite] Don't use O2 for inlining in break-inline-psymtab.exp

In test-case gdb.dwarf2/break-inline-psymtab.exp we use O2 to enable inlining
of bar into foo in break-inline-psymtab-2.c.

Instead, enforce inlining using __attribute__((always_inline)), to avoid any
optimization-related test issues.

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2020-04-02  Tom de Vries  <tdevries@suse.de>

	* gdb.dwarf2/break-inline-psymtab-2.c (bar): Add
	__attribute__((always_inline)).
	* gdb.dwarf2/break-inline-psymtab.exp: Don't use -O2.

---
 gdb/testsuite/gdb.dwarf2/break-inline-psymtab-2.c | 2 +-
 gdb/testsuite/gdb.dwarf2/break-inline-psymtab.exp | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/gdb/testsuite/gdb.dwarf2/break-inline-psymtab-2.c b/gdb/testsuite/gdb.dwarf2/break-inline-psymtab-2.c
index 38c69336f2..b7fe485b3a 100644
--- a/gdb/testsuite/gdb.dwarf2/break-inline-psymtab-2.c
+++ b/gdb/testsuite/gdb.dwarf2/break-inline-psymtab-2.c
@@ -19,7 +19,7 @@ extern int foo (void);
 
 int a;
 
-static inline int
+static inline int __attribute__((always_inline))
 bar (void)
 {
   a = 2;
diff --git a/gdb/testsuite/gdb.dwarf2/break-inline-psymtab.exp b/gdb/testsuite/gdb.dwarf2/break-inline-psymtab.exp
index adbe8620aa..344d7da0d5 100644
--- a/gdb/testsuite/gdb.dwarf2/break-inline-psymtab.exp
+++ b/gdb/testsuite/gdb.dwarf2/break-inline-psymtab.exp
@@ -16,8 +16,7 @@
 standard_testfile break-inline-psymtab.c break-inline-psymtab-2.c
 
 set sources [list $srcfile $srcfile2]
-set opts {debug optimize=-O2}
-if { [prepare_for_testing "failed to prepare" ${testfile} $sources $opts] } {
+if { [prepare_for_testing "failed to prepare" ${testfile} $sources] } {
     return -1
 }