Reserve space for scalar FP returns in the stack frame

tests_lit/llvm2ice_tests/elf_container.ll

 ; Tests that we generate an ELF container with fields that make sense,
 ; cross-validating against llvm-mc.
 
 ; For the integrated ELF writer, we can't pipe the output because we need
 ; to seek backward and patch up the file headers. So, use a temporary file.
 ; RUN: %p2i -i %s --filetype=obj --args -O2 --verbose none -o %t \
 ; RUN:   -allow-externally-defined-symbols \
 ; RUN:   && llvm-readobj -file-headers -sections -section-data \
 ; RUN:       -relocations -symbols %t | FileCheck %s
 
@@ skipping 368 matching lines @@
 ; CHECK:     Size: {{[1-9][0-9]*}}
 ; CHECK:     Link: 0
 ; CHECK:     Info: 0
 ; CHECK:     AddressAlignment: 1
 ; CHECK:     EntrySize: 0
 ; CHECK:   }
 
 
 ; CHECK: Relocations [
 ; CHECK:   Section ({{[0-9]+}}) .rel.text {
-; CHECK:     0x4 R_386_32 .L$float$80000000 0x0
-; CHECK:     0xC R_386_32 .L$float$3f9d70a0 0x0
-; CHECK:     0x24 R_386_32 .L$double$ffffffffffffffff 0x0
-; CHECK:     0x2C R_386_32 .L$double$fff7ffffffffffff 0x0
-; CHECK:     0x34 R_386_32 .L$double$fff8000000000003 0x0
+; CHECK:     0x7 R_386_32 .L$float$80000000 0x0
+; CHECK:     0xF R_386_32 .L$float$3f9d70a0 0x0
+; CHECK:     0x27 R_386_32 .L$double$ffffffffffffffff 0x0
+; CHECK:     0x2F R_386_32 .L$double$fff7ffffffffffff 0x0
+; CHECK:     0x37 R_386_32 .L$double$fff8000000000003 0x0
 ; CHECK:     0x{{.*}} R_386_PC32 memcpy
 ; CHECK:     0x{{.*}} R_386_PC32 memset
 ; CHECK:     0x{{.*}} R_386_PC32 external_foo
 ; CHECK:   }
 ; CHECK:   Section ({{[0-9]+}}) .rel.data {
 ; The set of relocations between llvm-mc and the integrated elf-writer
 ; are different. For local symbols, llvm-mc uses the section + offset within
 ; the section, while the integrated elf-writer refers the symbol itself.
 ; CHECK:     0x10 R_386_32 {{.*}} 0x0
 ; CHECK:     0x14 R_386_32 {{.*}} 0x0
@@ skipping 237 matching lines @@
 ; CHECK:        Symbol {
 ; CHECK:          Name: memset
 ; CHECK-NEXT:     Value: 0x0
 ; CHECK-NEXT:     Size: 0
 ; CHECK-NEXT:     Binding: Global
 ; CHECK-NEXT:     Type: None
 ; CHECK-NEXT:     Other: 0
 ; CHECK-NEXT:     Section: Undefined
 ; CHECK-NEXT:   }
 ; CHECK: ]